Forestry in India is a significant rural industry and a major environmental resource. India is one of the ten most forest-rich countries of the world. Together, India and 9 other countries account for 67 percent of the total forest area of the world. India's forest cover grew at 0.20% annually over 1990–2000, and has grown at the rate of 0.7% per year over 2000–2010, after decades where forest degradation was a matter of serious concern.
As of 2010, the Food and Agriculture Organization of the United Nations estimates India's forest cover to be about 68 million hectares, or 22% of the country's area The 2013 Forest Survey of India states its forest cover increased to 69.8 million hectares by 2012, per satellite measurements; this represents an increase of 5,871 square kilometers of forest cover in 2 years. However, the gains were primarily in northern, central and southern Indian states, while northeastern states witnessed a net loss in forest cover over 2010 to 2012. In 2018, the total forest and tree cover in India increased to 24.39% or 8,02,088 km2. It increased further to 24.56 percent or 807,276 square kilometres in 2019.
Unless India makes major, rapid and sustained effort to expand electricity generation and power plants, the rural and urban poor in India will continue to have to meet their energy needs through unsustainable destruction of forests and fuel wood consumption. India's dependence on fuel-wood and forestry products as a primary energy source is not only environmentally unsustainable, it is a primary cause of India's near-permanent haze and air pollution.
Forestry in India is more than just about wood and fuel. India has a thriving non-wood forest products industry, which produces latex, gums, resins, essential oils, flavours, fragrances and aroma chemicals, incense sticks, handicrafts, thatching materials and medicinal plants. About 60% of non-wood forest products production is consumed locally. About 50% of the total revenue from the forestry industry in India is in non-wood forest products category. (Full article...)
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Pollarding is a pruning system involving the removal of the upper branches of a tree, which promotes the growth of a dense head of foliage and branches. In ancient Rome, Propertius mentioned pollarding during the 1st century BCE. The practice has occurred commonly in Europe since medieval times, and takes place today in urban areas worldwide, primarily to maintain trees at a determined height or to place new shoots out of the reach of grazing animals.
Traditionally, people pollarded trees for one of two reasons: for fodder to feed livestock or for wood. Fodder pollards produced "pollard hay" for livestock feed; they were pruned at intervals of two to six years so their leafy material would be most abundant. Wood pollards were pruned at longer intervals of eight to fifteen years, a pruning cycle tending to produce upright poles favored for fencing and boat construction. Supple young willow or hazel branches may be harvested as material for weaving baskets, fences, and garden constructions such as bowers. Nowadays, the practice is sometimes used for ornamental trees, such as crape myrtles in southern states of the US.
Pollarding tends to make trees live longer by maintaining them in a partially juvenile state and by reducing the weight and windage of the top part of the tree. Older pollards often become hollow, so it can be difficult to determine age accurately. Pollards tend to grow slowly, with denser growth-rings in the years immediately after cutting. (Full article...)
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Australia has many forests of importance due to significant features, despite being one of the driest continents. , Australia has approximately 147 million hectares of native forest, which represents about 19% of Australia's land area. The majority of Australia's trees are hardwoods, typically eucalypts, rather than softwoods like pine. While softwoods dominate some native forests, their total area is judged insufficient to constitute a major forest type in Australia's National Forest Inventory. The Forests Australia website provides up-to-date information on Australia's forests. Detailed information on Australia's forests is available from Australia's State of the Forests Reports that are published every five years. (Full article...)
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The preindustrial age has been dubbed by Werner Sombart and others as the 'wooden age', as timber and firewood were the basic resources for energy, construction and housing. The development of modern forestry is closely connected with the rise of capitalism, the economy as a science and varying notions of land use and property. Roman Latifundiae, large agricultural estates, were quite successful in maintaining the large supply of wood that was necessary for the Roman Empire. Large deforestations came with the decline of the Romans. However already in the 5th century, monks in the then Byzantine Romagna on the Adriatic coast, were able to establish stone pine plantations to provide fuelwood and food. This was the beginning of the massive forest mentioned by Dante Alighieri in his 1308 poem Divine Comedy.
Similar sustainable formal forestry practices were developed by the Visigoths in the 7th century when, faced with the ever-increasing shortage of wood, they instituted a code concerned with the preservation of oak and pine forests. The use and management of many forest resources has a long history in China as well, dating back to the Han dynasty and taking place under the landowning gentry. A similar approach was used in Japan. It was also later written about by the Ming dynasty Chinese scholar Xu Guangqi (1562–1633).
In Europe, land usage rights in medieval and early modern times allowed different users to access forests and pastures. Plant litter and resin extraction were important, as pitch (resin) was essential for the caulking of ships, falking and hunting rights, firewood and building, timber gathering in wood pastures, and grazing animals in forests. The notion of "commons" (German "Allmende") refers to the underlying traditional legal term of common land. The idea of enclosed private property came about during modern times. However, most hunting rights were retained by members of the nobility which preserved the right of the nobility to access and use common land for recreation, like fox hunting. (Full article...)
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The Korea Forest Service is a central administrative agency under the Ministry of Agriculture, Food and Rural Affairs (MAFR), responsible for protecting and nurturing forests, increasing forest resources, developing forest products, conducting research on forest management and improvement, and is located in Daejeon Government Complex. In the past, during the national forestation campaign from 1973 to 1986, it was temporarily under the Ministry of Home Affairs (now the Ministry of the Interior and Safety), but returned to the Ministry of Agriculture, Forestry and Fisheries in 1987. However, as the agency's work was focused solely on maintaining and managing successful national forestation policies, questions were raised about its necessity for a period of time. Currently, the agency has transformed its identity into one that strives to generate continuous income through forest resources.
It is one of the government agencies that is highly likely to expand in the event of future North-South unification. In North Korea, there are many mountains, and it is expected that regional forest offices will be expanded to promote afforestation projects centering around Mount Mindungsan.
The Korea National Park Service, which is under the Ministry of Environment, had a long-standing conflict with the Korea Forest Service. Both agencies are in charge of forest-related work, but there were frequent conflicts due to differences in specific business objectives. While the Korea Forest Service also invests in forest development to promote forestry, the Korea National Park Service's primary objective is forest protection. Therefore, in 2012, an article was published between the two organization called "Let's Get Along."
Furthermore, it has a cooperative relationship with the Cultural Heritage Administration. High-quality lumber is essential for restoring, maintaining, and repairing traditional cultural properties, and in particular, Korean pine, also known as the "Geumgang Pine," is still a rare species. Therefore, the Korea Forest Service and the Cultural Heritage Administration are working together to create and manage Geumgang Pine plantations.
The current head of the organization is Nam Sung-hyun, who began his term in May 2022. (Full article...)
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A chainsaw (or chain saw) is a portable handheld powersaw that cuts with a set of teeth attached to a rotating chain driven along a guide bar.
Modern chainsaws are typically gasoline-, electric-, or battery-powered and are used in activities such as tree felling, limbing, bucking, pruning, cutting firebreaks in wildland fire suppression, harvesting of firewood, for use in chainsaw art and chainsaw mills, for cutting concrete, and cutting ice. Precursors to modern chainsaws were first used in surgery, with patents for wood chainsaws beginning in the late 19th century.
A chainsaw comprises an engine, a drive mechanism, a guide bar, a cutting chain, a tensioning mechanism, and safety features. Various safety practices and working techniques are used with chainsaws. (Full article...)
Although the primary motivation of salvage logging is economic, it has also been suggested that salvage logging may reduce erosion, reduce intensity of future wildfires, and slow buildup of pest insects. However, there is little evidence to support such claims, and most evidence supports the view that salvage logging is harmful to forest health and function.
As with other logging operations, the harvesting may be either by selection, thinning or clearcutting, and a regeneration plan may be put in place after the logging. Salvage logging may include removal of remaining live trees in predominantly dead stands. (Full article...)
Agroforestry can be practiced for economic, environmental, and social benefits, and can be part of sustainable agriculture. Apart from production, benefits from agroforestry include improved farm productivity, healthier environments, reduction of risk for farmers, beauty and aesthetics, increased farm profits, reduced soil erosion, creating wildlife habitat, less pollution, managing animal waste, increased biodiversity, improved soil structure, and carbon sequestration.
Agroforestry practices are especially prevalent in the tropics, especially in subsistence smallholdings areas, with particular importance in sub-Saharan Africa. Due to its multiple benefits, for instance in nutrient cycle benefits and potential for mitigating droughts, it has been adopted in the USA and Europe. (Full article...)
Although the total number of species is relatively small, conifers are ecologically important. They are the dominant plants over large areas of land, most notably the taiga of the Northern Hemisphere, but also in similar cool climates in mountains further south. Boreal conifers have many wintertime adaptations. The narrow conical shape of northern conifers, and their downward-drooping limbs, help them shed snow. Many of them seasonally alter their biochemistry to make them more resistant to freezing. While tropical rainforests have more biodiversity and turnover, the immense conifer forests of the world represent the largest terrestrial carbon sink. Conifers are of great economic value for softwoodlumber and paper production. (Full article...)
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A secondary forest (or second-growth forest) is a forest or woodland area which has regenerated through largely natural processes after human-caused disturbances, such as timber harvest or agriculture clearing, or equivalently disruptive natural phenomena. It is distinguished from an old-growth forest (primary or primeval forest), which has not recently undergone such disruption, and complex early seral forest, as well as third-growth forests that result from harvest in second growth forests. Secondary forest regrowing after timber harvest differs from forest regrowing after natural disturbances such as fire, insect infestation, or windthrow because the dead trees remain to provide nutrients, structure, and water retention after natural disturbances. Secondary forests are notably different from primary forests in their composition and biodiversity; however, they may still be helpful in providing habitat for native species, preserving watersheds, and restoring connectivity between ecosystems. (Full article...)
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Coppicing/ˈkɒpɪsɪŋ/ is the traditional method in woodland management of cutting down a tree to a stump, which in many species encourages new shoots to grow from the stump or roots, thus ultimately regrowing the tree. A forest or grove that has been subject to coppicing is called a copse/kɒps/ or coppice, in which young tree stems are repeatedly cut down to near ground level. The resulting living stumps are called stools. New growth emerges, and after a number of years, the coppiced trees are harvested, and the cycle begins anew. Pollarding is a similar process carried out at a higher level on the tree in order to prevent grazing animals from eating new shoots. Daisugi (台杉, where sugi refers to Japanese cedar), is a similar Japanese technique.
Many silviculture practices involve cutting and regrowth; coppicing has been of significance in many parts of lowland temperate Europe. The widespread and long-term practice of coppicing as a landscape-scale industry is something that remains of special importance in southern England. Many of the English language terms referenced in this article are particularly relevant to historic and contemporary practice in that area.
Typically a coppiced woodland is harvested in sections or coups on a rotation. In this way, a crop is available each year somewhere in the woodland. Coppicing has the effect of providing a rich variety of habitats, as the woodland always has a range of different-aged coppice growing in it, which is beneficial for biodiversity. The cycle length depends upon the species cut, the local custom, and the use of the product. Birch can be coppiced for faggots on a three- or four-year cycle, whereas oak can be coppiced over a fifty-year cycle for poles or firewood.
Trees being coppiced do not die of old age as coppicing maintains the tree at a juvenile stage, allowing them to reach immense ages. The age of a stool may be estimated from its diameter; some are so large—as much as 5.5 metres (18 ft) across—that they are thought to have been continually coppiced for centuries. (Full article...)
The fund provides support to indigenous rainforest peoples to assert and defend their rights, to define and promote sustainable development in their communities, and to challenge the activities and practices of governments or other entities which damage their environment and lands. The programs and projects are developed in partnership with local communities and representative indigenous NGOs. (Full article...)
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A temperate forest is a forest found between the tropical and boreal regions, located in the temperate zone. It is the second largest terrestrial biome, covering 25% of the world's forest area, only behind the boreal forest, which covers about 33%. These forests cover both hemispheres at latitudes ranging from 25 to 50 degrees, wrapping the planet in a belt similar to that of the boreal forest. Due to its large size spanning several continents, there are several main types: deciduous, coniferous, mixed forest, and rainforest. (Full article...)
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Thinning is a term used in agricultural sciences to mean the removal of some plants, or parts of plants, to make room for the growth of others. Selective removal of parts of a plant such as branches, buds, or roots is typically known as pruning.
In forestry, thinning is the selective removal of trees, primarily undertaken to improve the growth rate or health of the remaining trees. Overcrowded trees are under competitive stress from their neighbors. Thinning may be done to increase the resistance of the stand to environmental stress such as drought, insect infestation, extreme temperature, or wildfire. (Full article...)
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The International Tropical Timber Agreement (ITTA), 1983) is an agreement to provide an effective framework for cooperation between tropical timber producers and consumers and to encourage the development of national policies aimed at sustainable utilization and conservation of tropical forests and their genetic resources. The International Tropical Timber Organization was established under this agreement, which first opened for signature on 18 November 1983, then Entered into force on 1 April 1985. There were subsequent treaties, with an increasing number of signatories, in 1994 (ITTA2) and 2006 (ITTA3).
ITTA2 (1994) was drafted to ensure that by the year 2000 exports of tropical timber originated from sustainably managed sources and to establish a fund to assist tropical timber producers in obtaining the resources necessary to reach this objective. It further defined the mandate of the International Tropical Timber Organization. The agreement was opened for signature on 26 January 1994, and entered into force on 1 January 1997.
ITTA3 (2006) aimed to "promote the expansion and diversification of international trade in tropical timber from sustainably managed and legally harvested forests and to promote the sustainable management of tropical timber producing forests". It entered into force on 7 December 2011. (Full article...)
A crosscut saw (thwart saw) is any saw designed for cutting wood perpendicular to (across) the wood grain. Crosscut saws may be small or large, with small teeth close together for fine work like woodworking or large for coarse work like log bucking, and can be a hand tool or power tool.
The cutting edge of each tooth is angled in an alternating pattern. This design allows each tooth to act like a knife edge and slice through the wood in contrast to a rip saw, which tears along the grain, acting like a miniature chisel. Some crosscut saws use special teeth, called rakers, designed to clean out the cut strips of wood from the kerf. Crosscut saws generally have smaller teeth than rip saws.
Some saws, such as Japanese saws and those used by the ancient Egyptians, are designed to cut only on the pull stroke. Western saws, on the other hand, are designed to cut on the push stroke.[citation needed] Cross cut saws designed for log bucking and tree felling are designed to cut on the pull stroke. (Full article...)
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This is a list of historic schools of forestry, by founding date. Also included is information about each school's location, founder(s), present status, and (where applicable) closing date. Many remain active. (Full article...)
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Underwater logging is the process of logging trees from underwater forests. When artificial reservoirs and dams are built, large areas of forest are often inundated; although the trees die, the wood is often preserved. The trees can then be felled using special underwater machinery and floated up to the surface. One such machine is the sawfish harvester. There is an ongoing debate to determine whether or not underwater logging is a sustainable practice and if it is more environmentally sustainable than traditional logging.
Underwater logging has been introduced in select locations around the world, including Ghana's Lake Volta, the largest reservoir by surface area in the world.
A related form of logging consists of salvaging logs which loggers have abandoned after they became waterlogged and sank. This activity can be quite profitable, since the prime "targets" are decades-old trees of a size and species difficult or impossible to find in their natural habitat. (Full article...)
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The idea of an international organization for food and agriculture emerged in the late 19th and early 20th century, advanced primarily by Polish-born American agriculturalist and activist David Lubin. In May–June 1905, an international conference was held in Rome, Italy, which led to the creation of the International Institute of Agriculture (IIA) by the King of Italy, Victor Emmanuel III.
The IIA was the first intergovernmental organization to deal with the problems and challenges of agriculture on a global scale. It worked primarily to collect, compile, and publish data on agriculture, ranging from output statistics to a catalog of crop diseases. Among its achievements was the publication of the first agricultural census in 1930.
World War II effectively ended the IIA. During the war, in 1943, United States President Franklin D. Roosevelt called a League of Nations Conference on Food and Agriculture, which brought representatives from forty-four governments to The Omni Homestead Resort in Hot Springs, Virginia, from 18 May to 3 June to attend the Hot Springs Conference. The main impetus for the conference was the British-born Australian economist Frank L. McDougall, who since 1935 had advocated for an international forum to address hunger and malnutrition.
The Conference ended with a commitment to establish a permanent organization for food and agriculture, which was achieved on 16 October 1945 in Quebec City, Canada, following the Constitution of the Food and Agriculture Organization. The first session of the FAO Conference began the same day in the Château Frontenac in Quebec City and ended on 1 November 1945. This was led by Sir John Boyd Orr where his work on ending world hunger and creation of FAO resulted in him winning the Nobel Peace Prize in 1949.
After the war, the IIA was officially dissolved by resolution of its Permanent Committee on 27 February 1948. Its functions, facilities, and mandate were then transferred to the newly established FAO, which maintained its headquarters in Rome.
The FAO's initial functions supported agricultural and nutrition research and provided technical assistance to member countries to boost production in agriculture, fishery, and forestry. Beginning in the 1960s, it focused on efforts to develop high-yield strains of grain, eliminate protein deficiency, promote rural employment, and increase agricultural exports. The FAO recognized the decrease of these resources as an urgent problem in 1961 and created a joint collaboration with the International Biological Program (IBP) in 1967. To that end, it joined the UN General Assembly in creating the UN World Food Programme, the largest humanitarian organization addressing hunger and promoting food security.
The FAO launched what would become the FAO Money and Medals Programme (MMP) in 1968. FAO issued collector art medals in various series to bring attention to FAO's goals and missions. This program was responsible for over a hundred medal designs issued to the collecting public. A thirtieth anniversary medal of the MMP was issued in 1998.
In 1974, in response to famine in Africa, the FAO convened the first World Food Summit to address widespread hunger, malnutrition, and food insecurity. The meeting resulted in a proclamation that "every man, woman, and child has the inalienable right to be free from hunger and malnutrition to develop their physical and mental faculties" and a global commitment to eradicate these issues within a decade. A subsequent summit in 1996 addressed the shortcomings in achieving this goal while establishing a strategic plan for eliminating hunger and malnutrition into the 21st century.
Every year, FAO publishes a number of major 'State of the World' reports related to food, agriculture, forestry, fisheries and natural resources. (Full article...)
Although thinning originated as a man-made forest management tool, aimed at increasing timber yields, the shift from production forests to multifunctional forests brought with it the cutting of trees to manipulate an ecosystem for various reasons, ranging from removing non-native species from a plot to removing poplars growing on a riverside beach aimed at recreational use.
Since the 1970s, leaving the thinned trees on the forest floor has become an increasingly common policy: wood can be decomposed in a more natural fashion, playing an important role in increasing biodiversity by providing habitat to various invertebrates, birds and small mammals. Many fungi (e.g. Calocera viscosa) and mosses are saproxylic or epixylic as well (e.g. Marchantiophyta) – some moss species completing their entire life-cycle on a single log.
Where trees are managed under a commercial regime, competition is reduced by removing adjacent stems that exhibit less favourable timber quality potential. When left in a natural state trees will "self-thin", but this process can be unreliable in some circumstances. Examples of this can be found in the Buxus–Ironbark forests and woodlands of Victoria (Australia) where a large proportion of trees are coppice, resultant from timber cutting in decades gone by. (Full article...)
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The Forest Research Institute Malaysia (FRIM; Malay: Institut Penyelidikan Perhutanan Malaysia) is a statutory agency of the Government of Malaysia, under the Natural Resources and Environmental Sustainability (NRES). FRIM promotes sustainable management and optimal use of forest resources in Malaysia by generating knowledge and technology through research, development and application in tropical forestry. FRIM is located in Kepong, near Kuala Lumpur.
FRIM is the world's oldest and largest re-created tropical rain forest. (Full article...)
Paper is a thin sheet material produced by mechanically or chemically processing cellulosefibres derived from wood, rags, grasses, or other vegetable sources in water, draining the water through a fine mesh leaving the fibre evenly distributed on the surface, followed by pressing and drying. Although paper was originally made in single sheets by hand, almost all is now made on large machines—some making reels 10 metres wide, running at 2,000 metres per minute and up to 600,000 tonnes a year. It is a versatile material with many uses, including printing, painting, graphics, signage, design, packaging, decorating, writing, and cleaning. It may also be used as filter paper, wallpaper, book endpaper, conservation paper, laminated worktops, toilet tissue, currency, and security paper, or in a number of industrial and construction processes.
The papermaking process developed in east Asia, probably China, at least as early as 105 CE, by the Han court eunuchCai Lun, although the earliest archaeological fragments of paper derive from the 2nd century BCE in China. The modern pulp and paper industry is global, with China leading its production and the United States following. (Full article...)
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Lumberjack is a mostly North American term for workers in the logging industry who perform the initial harvesting and transport of trees. The term usually refers to loggers in the era before 1945 in the United States, when trees were felled using hand tools and dragged by oxen to rivers.
The work was difficult, dangerous, intermittent, low-paying, and involved living in primitive conditions. However, the men built a traditional culture that celebrated strength, masculinity, confrontation with danger, and resistance to modernization. (Full article...)
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The Rainforest Alliance is an international non-governmental organization (NGO) with staff in more than 20 countries and operations in more than 70 countries. It was founded in 1987 by Daniel Katz, an American environmental activist, who serves as the chair of the board of directors. The NGO states that its mission is "to create a more sustainable world by using social and market forces to protect nature and improve the lives of farmers and forest communities." Its work includes the provision of an environmental certification for sustainability in agriculture. In parallel to its certification program, the Rainforest Alliance develops and implements long-term conservation and community development programs in a number of critically important tropical landscapes where commodity production threatens ecosystem health and the well-being of rural communities. (Full article...)
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Basal area is the cross-sectional area of trees at breast height (1.3m or 4.5 ft above ground). It is a common way to describe stand density. In forest management, basal area usually refers to merchantable timber and is given on a per hectare or per acre basis. If one cut down all the merchantable trees on an acre at 4.5 feet (1.4 m) off the ground and measured the square inches on the top of each stump (πr*r), added them all together and divided by square feet (144 sq inches per square foot), that would be the basal area on that acre. In forest ecology, basal area is used as a relatively easily-measured surrogate of total forest biomass and structural complexity, and change in basal area over time is an important indicator of forest recovery during succession . (Full article...)
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Ecoforestry has been defined as selection forestry or restoration forestry. The main idea of ecoforestry is to maintain or restore the forest to standards where the forest may still be harvested for products on a sustainable basis. Ecoforestry is forestry that emphasizes holistic practices which strive to protect and restore ecosystems rather than maximize economic productivity. Sustainability of the forest also comes with uncertainties. There are other factors that may affect the forest furthermore than that of the harvesting. There are internal conditions such as effects of soil compaction, tree damage, disease, fire, and blow down that also directly affect the ecosystem. These factors have to be taken into account when determining the sustainability of a forest. If these factors are added to the harvesting and production that comes out of the forest, then the forest will become less likely to survive, and will then become less sustainable.
Since the forest is considered an ecosystem, it is dependent on all of the living and non-living factors within itself. This is a major part of why the forest needs to be sustainable before it is harvested. For example, a tree, by way of photosynthesis, converts sunlight to sugars for respiration to keep the tree alive. The remains of the converted sugars is left in roots for consumption by the organisms surrounding the tree in the habitat. This shows the productivity of an ecosystem with its inhabitants. Productivity within the ecosystem cannot come to fruition unless the forest is sustainable enough to be harvested. If most individual organisms of the ecosystem vanish, the ecosystem itself is at risk. Once that happens, there is no longer any forest to harvest from. The overall productivity of a system can be found in an equation where the Net Primary Production, or NPP, is equal to the Gross Primary Production, or GPP, minus the Respiration, or R. The formula is the NPP = GPP - R. The NPP is the overall efficiency of the plants in the ecosystem. Through having a constant efficiency in NPP, the ecosystem is then more sustainable. The GPP refers to the rate of energy stored by photosynthesis in plants. The R refers to the maintenance and reproduction of plants from the energy expended.
Ecoforestry has many principles within the existence of itself. It covers sustainable development and the fair harvesting of the organisms living within the forest ecosystem. There have been many proposals of principles outlined for ecoforestry. They are covered over books, articles, and environmental agencies. All of the principles relate to the idea that in ecoforestry, less should be harvested, and diversity must be managed. Through harvesting less, there is enough biomass left in the forest, so that the forest may stay healthy and still stay maintained. It will grow at a sustainable level annually, and thus it will be able to still be harvested the following year. Through management of the diversity, species may cohabitate in an ecosystem where the forest may feed off of other species in its growth and production. The Principles of Ecoforestry may be found below. (Full article...)
Although the total number of species is relatively small, conifers are ecologically important. They are the dominant plants over large areas of land, most notably the taiga of the Northern Hemisphere, but also in similar cool climates in mountains further south. Boreal conifers have many wintertime adaptations. The narrow conical shape of northern conifers, and their downward-drooping limbs, help them shed snow. Many of them seasonally alter their biochemistry to make them more resistant to freezing. While tropical rainforests have more biodiversity and turnover, the immense conifer forests of the world represent the largest terrestrial carbon sink. Conifers are of great economic value for softwoodlumber and paper production. (Full article...)
Aerial seeding is considered a broadcast method of seeding. It is often used to spread different grasses and legumes to large areas of land that are in need of vegetative cover after fires. Large wildfires can destroy large areas of plant life resulting in erosion hazards. Aerial seeding may quickly and effectively reduce erosion hazards and suppress growth of invasive plant species. Aerial seeding is an alternative to other seeding methods where terrain is extremely rocky or at high elevations or otherwise inaccessible. Problems with direct broadcast include germination, pests and seed predation by rodents or other wild animals. Transplanting seedlings from a plant nursery to the field is a more effective sowing technique. Aerial seeding has a low yield and require 25% to 50% more seeds than drilled seeding to achieve the same results.
Aerial seeding is also often used to plant cover crops. Some plants often seeded by this method are perennial rye (Timothy, Red Fescue, Red Top, Bluegrass), Sudan grass, soy beans, buckwheat, hairy vetch, corn, cereal rye, winter wheat, oats, mammoth or medium red clover, sweet clover, berseem clover and crimson clover (Timothy). (Full article...)
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Variable retention is a relatively new silvicultural system that retains forest structural elements for at least one rotation in order to preserve environmental values associated with structurally complex forests.
Some examples for environmental values are forest cover connectivity, soil stabilization, microclimate under retained trees, habitats associated with live or dead trees and species diversity due to habitat preservation, and wildlife corridor preservation. Variable retention also aids in emulation of natural disturbances by leaving behind some residual structure from previous stand which is typical for stand replacing disturbances Traditional silviculture systems such as clearcut, patch cut, shelterwood, etc. are focused on maximizing timber production and future regeneration of the trees. Variable retention on the other hand is focused on what is retained (Full article...)
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A list of tree species, grouped generally by biogeographic realm and specifically by bioregions, and shade tolerance. Shade-tolerant species are species that are able to thrive in the shade, and in the presence of natural competition by other plants. Shade-intolerant species require full sunlight and little or no competition. Intermediate shade-tolerant trees fall somewhere in between the two. (Full article...)
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Carl Alwin Schenck (25 March 1868 – 17 May 1955) was a German forester and pioneering forestry educator. When Schenck came to the United States to work for George W. Vanderbilt at the Biltmore Estate, he became the third formally trained forester in the United States. He established and operated the Biltmore Forest School, the first forestry school in North America, on Vanderbilt's property.
Schenck also helped create the forestry school at Sewanee: The University of the South, taught at the University of Montana in Missoula and the University of Giessen, and wrote textbooks. His teachings comprise the foundation of forestry education in the United States. However, Schenck's contributions were rarely recognized in histories of forestry, in part, because he was German during an era when the United States fought two wars against Germany. The New York Times described him as "the most influential person in making forestry in this country a science and a profession." (Full article...)
A nature reserve (also known as a wildlife refuge, wildlifesanctuary, biosphere reserve or bioreserve, natural or nature preserve, or nature conservation area) is a protected area of importance for flora, fauna, funga, or features of geological or other special interest, which is reserved and managed for purposes of conservation and to provide special opportunities for study or research. They may be designated by government institutions in some countries, or by private landowners, such as charities and research institutions. Nature reserves fall into different IUCN categories depending on the level of protection afforded by local laws. Normally it is more strictly protected than a nature park. Various jurisdictions may use other terminology, such as ecological protection area or private protected area in legislation and in official titles of the reserves. (Full article...)
A cord is the amount of wood that, when "racked and well stowed" (arranged so pieces are aligned, parallel, touching and compact), occupies a volume of 128 cubic feet (3.62 m3). This corresponds to a well-stacked woodpile 4 feet (122 cm) high, 8 feet (244 cm) wide, and 4 feet (122 cm) deep; or any other arrangement of linear measurements that yields the same volume.
The name cord probably comes from the use of a cord or string to measure it.
The cord-foot was a US unit of volume for stacked firewood, four feet long, four feet wide and one foot high—equal to one eighth of a cord. The symbol for the unit was cd-ft. (Full article...)
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Cork is an impermeablebuoyant material. It is the phellem layer of bark tissue which is harvested for commercial use primarily from Quercus suber (the cork oak), which is native to southwest Europe and northwest Africa. Cork is composed of suberin, a hydrophobic substance. Because of its impermeable, buoyant, elastic, and fire retardant properties, it is used in a variety of products, the most common of which is wine stoppers.
The montado landscape of Portugal produces approximately half of the cork harvested annually worldwide, with Corticeira Amorim being the leading company in the industry. Cork was examined microscopically by Robert Hooke, which led to his discovery and naming of the cell.
A feller buncher is a type of harvester used in logging. It is a motorized vehicle with an attachment that can rapidly gather and cut a tree before felling it.
Feller is a traditional name for someone who cuts down trees, and bunching is the skidding and assembly of two or more trees. A feller buncher performs both of these harvesting functions and consists of a standard heavy equipment base with a tree-grabbing device furnished with a chain-saw, circular saw or a shear—a pinching device designed to cut small trees off at the base. The machine then places the cut tree on a stack suitable for a skidder, forwarder, or yarder for transport to further processing such as delimbing, bucking, loading, or chipping.
Some wheeled feller bunchers lack an articulated arm, and must drive close to a tree to grasp it.
Interest in cellulosic ethanol is driven by its potential to replace ethanol made from corn or sugarcane. Since these plants are also used for food products, diverting them for ethanol production can cause food prices to rise; cellulose-based sources, on the other hand, generally do not compete with food, since the fibrous parts of plants are mostly inedible to humans. Another potential advantage is the high diversity and abundance of cellulose sources; grasses, trees and algae are found in almost every environment on Earth. Even municipal solid waste components like paper could conceivably be made into ethanol. The main current disadvantage of cellulosic ethanol is its high cost of production, which is more complex and requires more steps than corn-based or sugarcane-based ethanol.
Cellulosic ethanol received significant attention in the 2000s and early 2010s. The United States government in particular funded research into its commercialization and set targets for the proportion of cellulosic ethanol added to vehicle fuel. A large number of new companies specializing in cellulosic ethanol, in addition to many existing companies, invested in pilot-scale production plants. However, the much cheaper manufacturing of grain-based ethanol, along with the low price of oil in the 2010s, meant that cellulosic ethanol was not competitive with these established fuels. As a result, most of the new refineries were closed by the mid-2010s and many of the newly founded companies became insolvent. A few still exist, but are mainly used for demonstration or research purposes; as of 2021, none produces cellulosic ethanol at scale. (Full article...)
The coral catshark (Atelomycterus marmoratus) is a species of catshark in the family Scyliorhinidae. It is common on shallow coral reefs across the Indo-West Pacific, from Pakistan to New Guinea. Reaching up to 70 cm (28 in) in length, the coral catshark has an extremely slender body, a short head and tail, and two dorsal fins that are angled backwards. It can be identified by the numerous black and white spots on its back, sides, and fins, which often merge to form horizontal bars. Furthermore, adult males have distinctively long and thin claspers.
Probably the smallest species of hammerhead shark, the scalloped bonnethead measures up to 92 centimetres (36 in) long. Its mallet-shaped head, called a cephalofoil, is moderately wide (24–29% of total length) and elongated lengthwise. The front margin is broadly arched, with shallow lateral and medial indentations, and no prenarial grooves. The mouth is small and strongly arched. The anal fin is long and has a nearly straight rear margin. Its coloration is gray above and white below, with no prominent fin markings. The similar scoophead (S. media) can be distinguished by a shorter snout, a broader mouth, and a deeply concave anal fin margin.
Like other hammerheads, the scalloped bonnethead is viviparous, with presumably two pups per litter. The young are born at 23 centimetres (9.1 in) or above; an adolescent male has been recorded at 51 centimetres (20 in) long, and an adult at 67 centimetres (26 in). It may be taken by local inshore fisheries, but data is lacking. It feeds on or near the bottom, on crustaceans, molluscs, cephalopods, echinoderms, and bony fishes. (Full article...)
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The sawback angelshark (Squatina aculeata) is an angelshark of the familySquatinidae It is one of rarest species of sharks known to date, and one of the three species of angelsharks that inhabits the Mediterranean. The Sawback angelshark lives in sandy and muddy bottoms of the ocean at depths of 30-500m. (Full article...)
The honeycomb Izak or Natal Izak (Holohalaelurus favus) is a type of catshark in the Western Indian Ocean, near South Africa. It reaches a maximum length of around 50 cm. Since the mid-1970s, no specimens have been collected, even with recent biodiversity research cruises (2002 and 2003). (Full article...)
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The black dogfish (Centroscyllium fabricii) is a species of dogfish shark in the familyEtmopteridae. It is common over the outer continental shelf and continental slope at depths of 180–2,250 m (590–7,380 ft). Females generally inhabit deeper water than males, and depending on the region, smaller sharks may occur at different depths than larger ones. This species is distributed widely in the Atlantic Ocean, from Greenland and Iceland to Virginia and West Africa in the north, and off southwestern Africa and Argentina in the south. The largest member of its family, the black dogfish, typically measures 60–75 cm (24–30 in) long. It has a stocky, dark brown body that is darker below than above, and bears scattered, minute bioluminescent organs. Its two dorsal fins are preceded by stout spines, and the anal fin is absent.
It is relatively small with skin of a light-brownish color, and it can be found in the Pacific Ocean. Not much is known about this species, and no attacks on humans from this animal have been recorded. It resembles the copper shark and a sand tiger shark, yet it is much smaller than both. It also has a small, slender body, and five gills in front of its pectoral fins. (Full article...)
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The shortnose sawshark, (Pristiophorus nudipinnis) or southern sawshark, is a sawshark of the familyPristiophoridae. The body of this shark is slightly compressed, and its rostrum is narrow. The two dorsal fins are almost identical in size. In color, the dorsal side of this sawshark tends to be uniformly slate gray, with few or no markings. The ventral side is pale white or cream. Females reach around 124 cm (49 in) long, and males reach around 110 cm (43 in) long. These sharks can live up to 9 years. (Full article...)
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The Oman bullhead shark, Heterodontus omanensis, is a bullhead shark of the family Heterodontidae found in the tropical western Indian Ocean around central Oman, from the surface to a depth of 72 m (236 ft) on the continental shelf. This species has an average length of 56 cm (22 in) and can reach a maximum length of 61 cm (24 in). This shark was described in 2005, making it one of the most recently described of its genus. The Oman bullhead shark likely is accidentally caught as bycatch, putting the species at risk. (Full article...)
The creek whaler (Carcharhinus fitzroyensis) is a common species of requiem shark, and part of the family Carcharhinidae, endemic to northern Australia. It frequents shallow waters close to shore, including estuaries. This small, stocky shark usually grows to 1.0–1.3 m (3.3–4.3 ft) long and is brownish in color without conspicuous fin markings. It can be identified by its long snout, large, triangular pectoral fins, and large, anteriorly positioned first dorsal fin.
The diet of the creek whaler consists mainly of small teleost fishes and crustaceans. It is viviparous, with the unborn young being sustained through a placental connection. The defined mating season lasts from May to July. Females give birth to one to seven pups annually, following a gestation period of seven to 9 months. A small number of creek whalers are caught incidentally in inshoregillnets and used for food, but the effect of fishing on its population seems to be inconsequential. As a result, the IUCN has listed this species under Least Concern. (Full article...)
Paragaleus tengi is distinctive for its color and size. Specifically, its solid grey dorsal (upper) color, short snout, and 2-3 rows of lower teeth are a few of the characteristic traits that aid in distinguishing between this species of shark and others, like the Paragaleus pectoralis (White & Harris, 2013).
The leafscale gulper shark (Centrophorus squamosus) is a dogfish of the familyCentrophoridae. C. squamosus is reported to have a lifespan of approximately 70 years, based on otolith ring counts. It was the first described species in the genus Centrophorus, which now contains 13 species. (Full article...)
The crested bullhead shark (Heterodontus galeatus) is an uncommon species of bullhead shark, in the family Heterodontidae. It lives off the coast of eastern Australia from the coast to a depth of 93 m (305 ft). This shark can be distinguished from other members of its family by the large size of the ridges above its eyes and by its color pattern of large dark blotches. It typically attains a length of 1.2 m (3.9 ft).
The pygmy shark (Euprotomicrus bispinatus), the second-smallest of all the shark species after the dwarf lanternshark, is a squaliform shark of the family Dalatiidae, the only member of the genusEuprotomicrus. Their lengths are up to about 25 cm (10 in) for females and about 22 cm (8.7 in) for males.
The copper shark (Carcharhinus brachyurus), bronze whaler, or narrowtooth shark is a species of requiem shark found mostly in temperatelatitudes. It is distributed in a number of separate populations in the northeastern and southwestern Atlantic, off southern Africa, in the northwestern and eastern Pacific, and around Australia and New Zealand, with scattered reports from equatorial regions. The species can be found from brackish rivers and estuaries to shallow bays and harbors, to offshore waters 100 m (330 ft) deep or more. Females are found apart from males for most of the year, and conduct seasonal migrations. A large species reaching 3.3 m (11 ft) long, the copper shark is difficult to distinguish from other large requiem sharks. It is characterized by its narrow, hook-shaped upper teeth, lack of a prominent ridge between the dorsal fins, and plain bronze coloration.
Feeding mainly on cephalopods, bony fishes, and other cartilaginous fishes, the copper shark is a fast-swimming predator that has been known to hunt in large groups, using their numbers to their advantage; however for most of the time they remain solitary. Off South Africa, this species associates closely with the annual sardine run, involving millions of southern African pilchard (Sardinops sagax). Like other requiem sharks, it is viviparous, with the developing embryos mainly nourished through a placental connection formed from the depleted yolk sac. Females bear litters of 7 to 24 pups every other year in coastal nursery areas, after a gestation period of 12 or perhaps as long as 21 months. It is extremely slow-growing, with males and females not reaching maturity until 13–19 and 19–20 years of age respectively.
This species is valued by commercial and recreational fisheries throughout its range, and utilized as food. The species population size is unknown, but the IUCN's Red List assesses the species as vulnerable because it is very susceptible to population depletion due to its low growth and reproductive rates and because its numbers are believed to have declined in some areas.
Copper sharks only attack humans infrequently, but the species places tenth in the number of unprovoked attacks on people. However, the actual number of recorded shark attacks is low – 15 non-fatal, unprovoked attacks and only one fatal unprovoked attack. (Full article...)
Maturing at under 62–66 cm (24–26 in) long, the blind shark has a stocky, grayish to brownish body with white flecks and darker bands that fade with age. Its head is wide, flattened, and blunt, with small eyes on top and a pair of long barbels underneath. It has large pectoral fins, two nearly equal-sized dorsal fins placed far back on the body, and an anal fin placed close to the caudal fin. The blind shark feeds primarily on small invertebrates and bony fishes. It is aplacental viviparous with females bearing litters of 7–8 pups in the summer. This small shark adapts readily to being kept in captivity. It is not valued by either commercial or recreational fishers, and its hardiness means that incidentally caught individuals are likely to be returned to the water alive. In the absence of substantial threats to its population, the International Union for Conservation of Nature has assessed it as of Least Concern. (Full article...)
Poroderma is a genus of catsharks, and part of the familyScyliorhinidae. The color of these sharks are usually grey with dark stripes. They are found in South Africa and are nocturnal. They live preferably in shore areas, close to the bottom, to depths of 100 m. They prefer small caves and crevices. Their diet usually consists of crustaceans, but they also feed on small fish. Their average size is between 60 and 80 cm, with a maximum total length of about 100 cm. Their birth size is about 15 cm. They are harmless to humans. (Full article...)
Members of the order have two dorsal fins, which usually possess spines, they usually have a sharp head, no anal fin or nictitating membrane, and five to seven gill slits. In most other respects, however, they are quite variable in form and size. Most species of the squaliform order live in saltwater or brackish water. They are found worldwide, from northern to tropical waters, and from shallow coastal seas to the open ocean.
All members of the family Etmoperidae and Dalatiidae and Zameus squamulosus possess photophores, luminous organs, and exhibit intrinsic bioluminescence. Bioluminescence evolved once in Squaliformes, approximately 111–153 million years ago, and helped the Squaliformes radiate and adapt to the deep sea. The common ancestor of Dalatiidae, Etmopteridae, Somniosidae, and Oxynotidae possessed a luminous organ and used bioluminescence for camouflage by counterillumination. Counterillumination is an active form of camouflage in which an organism emits light to match the intensity of downwelling light to hide from predators below. Currently, bioluminescence provides different functions for Squaliformes based on the family. Dalatiidae and Zameus squamulosus possess simple photophores and use bioluminescence for ventral counter-illumination. Etmopteridae possess more complex photophores and utilize bioluminescence for ventral counter illumination as well as species recognition. (Full article...)
It is found widely along coastlines in the Indo-Pacific, preferring reefs, sandy flats, and seagrass beds from very shallow water to a depth of 70 m (230 ft). With a cylindrical body and a broad, flattened head, the tawny nurse shark is quite similar in appearance to the nurse shark (Ginglymostoma cirratum) of the Atlantic and East Pacific, from which it can be distinguished by its pointed-tipped dorsal fins and narrow, sickle-shaped pectoral fins. The maximum recorded length of the tawny nurse shark is 3.2 m (10 ft).
Nocturnal in habits, the tawny nurse shark tends to spend the day resting in piles of two dozen or more individuals inside caves or under ledges. At night, it is an active-swimming predator that uses a powerful suction force to extract prey from inside holes and crevices. The diet of this species consists mainly of octopus, though they also take other invertebrates, small bony fishes, and rarely sea snakes. It is aplacental viviparous, meaning the embryos hatch from egg capsules inside the mother. It is the only carpet shark in which the embryos are oophagous, feeding on eggs produced by the mother while inside the uterus. The litter size may be as small as one or two, based on the large size of near-term embryos.
Compared to the nurse shark, the tawny nurse shark has a more placid disposition and will often allow divers to touch and play with it. However, it should be accorded respect due to its powerful jaws and sharp teeth. This species is caught by commercial fisheries across most of its range for meat, fins, liver oil, leather, and fishmeal. It is also esteemed as a game fish off Queensland, Australia, and is known for its habit of spitting water in the faces of its captors. The International Union for Conservation of Nature (IUCN) has assessed the tawny nurse shark as Vulnerable, with subpopulations in several areas already diminished or extirpated. (Full article...)
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The Indonesian houndshark (Hemitriakis indroyonoi) is a species of houndshark in the genus Hemitriakis. It is a tropical houndshark, known from the eastern Indonesian islands of Bali and Lombok, in the Indian Ocean. It was described by William T. White, Leonard J.V. Compagno, and Dharmadi in 2009. Females give birth to live young, with no placenta or yolk sac, and can have between six and 11 pups in one litter. When born, the pups measure 28–30 cm long. At first maturity, the houndsharks measure 90 cm, and males can go on to reach a maximum length of 120 cm, while females can reach a maximum length of 115 cm. (Full article...)
The Seychelles gulper shark (Centrophorus seychellorum) is a species of fish in the family Centrophoridae found in Alphonse island in Seychelles. This species is distinguished by having large tip of snout to first dorsal distance of 34% TL; first dorsal fin high (7% TL); second dorsal fin base long (9.8% TL); long snout (12.2% TL); uniformly grey with tip and the trailing edge of dorsal fins blackish. It is one of 11 described species in the genus Centrophorus. (Full article...)
Squalus crassispinus is a rare, small and slender dogfish with a broad head and short snout. There is a broad, small medial barbel on the anterior nasal flaps. The pectoral fin has a shallowly concave posterior margin. The first dorsal fin is moderately high, and both dorsal fin spines are very stout.
Coloration is light grey above, paler below, with no white spots. The pale dorsal fins have dusky tips.
The rough longnose shark (Deania hystricosa) is a little-known deepwater dogfish. This species was described by Samuel Garman in 1906 and originally named Acanthidium hystricosa.
The rough longnose dogfish has an extremely long snout, no anal fin, small grooved dorsal spines, and rough, pitchfork-shaped dermal denticles. The first dorsal fin is long and narrow.
Maximum length is 109 cm. Found in the Eastern Atlantic around Madeira and in the western Pacific around southern Japan, this shark is rarely seen, but lives between 600 and 1,000 m. It is ovoviviparous with probably around 12 pups per litter.
The scalloped hammerhead (Sphyrna lewini) is a species of hammerhead shark in the familySphyrnidae. It was originally known as Zygaena lewini. The Greek word sphyrna translates into "hammer" in English, referring to the shape of this shark's head, which is its most distinguishing characteristic. The shark's eyes and nostrils are at the tips of the extensions. It is a fairly large hammerhead, but is still smaller than both the great and smooth hammerheads.
This shark is also known as the bronze, kinky-headed, or southern hammerhead. It primarily lives in warm, temperate, and tropical coastal waters all around the globe between latitudes46°N and 36°S, down to a depth of 500 m (1,600 ft). It is the most common of all hammerheads. (Full article...)
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The bigeye thresher (Alopias superciliosus) is a species of thresher shark, family Alopiidae, found in temperate and tropical oceans worldwide. Like the other thresher sharks, nearly half its total length consists of the elongated upper lobe of the tail fin. Its common name comes from its enormous eyes, which are placed in keyhole-shaped sockets that allow them to be rotated upward. This species can also be distinguished by a pair of deep grooves on the top of its head, from which its scientific name is derived.
The large eyes of the bigeye thresher are adapted for hunting in low light conditions. It is one of the few sharks that conduct a diel vertical migration, staying in deep water during the day and moving into surface waters at night to feed. To protect its sensitive brain and eyes from the temperature changes accompanying these movements, the bigeye thresher has a vascular exchange system called the rete mirabile around those organs. This species feeds mainly on fish and squid, which are stunned via whip-like strikes of the long tail. Bigeye threshers are ovoviviparous, usually bearing litters of two pups. The embryos are oophagous and feed on ova produced by the mother while inside the uterus. This shark is caught by commercial fisheries across its range; the meat is not highly regarded but the skin, fins, and liver oil are valued. It has been assessed as Vulnerable by the International Union for Conservation of Nature (IUCN). (Full article...)
The broadfin sawtail catshark (Galeus nipponensis) is a common species of catshark, part of the familyScyliorhinidae. It is found on or near the bottom at depths of 150–540 m (490–1,770 ft), from southeastern Japan to the East China Sea. A slender species growing to 68 cm (27 in) long, this shark is characterized by a fairly long, pointed snout, a series of indistinct, dark saddles along its back and tail, and a prominent crest of enlarged dermal denticles along the dorsal edge of its caudal fin. In addition, adult males have very long claspers that reach past the anal fin. The broadfin sawtail catshark is an opportunistic predator of bony fishes, cephalopods, and crustaceans, with immature and mature sharks being primarily piscivorous. It is oviparous and reproduces year-round. (Full article...)
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The pyjama shark or striped catshark (Poroderma africanum) is a species of catshark, and part of the familyScyliorhinidae, endemic to the coastal waters of South Africa. This abundant, bottom-dwelling species can be found from the intertidal zone to a depth of around 100 m (330 ft), particularly over rocky reefs and kelp beds. With a series of thick, parallel, dark stripes running along its stout body, the pyjama shark has an unmistakable appearance. It is additionally characterized by a short head and snout with a pair of slender barbels that do not reach the mouth, and two dorsal fins that are placed far back on the body. It can grow up to a length of 1.1 m (3.6 ft) long.
The pyjama shark is primarily nocturnal, spending most of the day lying motionless and hidden in a cave or crevice or among vegetation. It often forms groups, particularly during summer. This species is an opportunistic predator that feeds on a wide variety of fishes and invertebrates; it favors cephalopods and frequents the spawning grounds of the chokka squid (Loligo reynaudi). When threatened, it curls into a circle with its tail covering its head. Reproduction is oviparous, with females laying rectangular, dark brown egg cases two at a time year-round. This small and harmless shark adapts well to captivity and is commonly displayed in public aquariums. It is often caught as a bycatch of commercial and recreational fisheries. Many are killed by fishers who regard them as pests. Although there are no data suggesting its numbers have declined, the International Union for Conservation of Nature (IUCN) has assessed the pyjama shark as least concern. (Full article...)
The Ulu Tutong Dam is an embankment dam on the Sungai Tutong River in Tutong District, Brunei. The primary purpose of the dam is to increase water supply in Tutong and Brunei-Muara Districts by as much as 156,000,000 m3 (126,000 acre⋅ft) annually. It has a normal reservoir volume of 100,000,000 m3 (81,000 acre⋅ft), making it the largest water supply project in the country. In February 2010 Sinohydro won the bid to construct the US$63 million project and construction began soon thereafter. It was originally expected to be complete in February 2014 but the date was pushed to February 2015 due to difficulties at the construction site. It was eventually fully completed in February 2017. In July 2018, it was officially renamed Ulu Tutong Golden Jubilee Dam by Sultan Hassanal Bolkiah. The dam is owned by the Public Works Department of Brunei. (Full article...)
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The Cingino Dam is a gravity masonry dam located 7 kilometres (4 mi) southwest of Antrona Schieranco, Province of Verbano-Cusio-Ossola in Piedmont, Italy. The dam creates Lago Cingino (or Cingino reservoir) which is fed by the Antigine and Troncone streams. The reservoir has a surface area of 0.14 square kilometres (0.1 sq mi) and is maximum 2,262 metres (7,421 ft) above sea level, typically 2,250 metres (7,382 ft). It is one of five reservoirs within a hydroelectric complex in the Valle Antrona and helps supply the Campliccioli Power Plant with water for power production.
The dam became an internet sensation due to pictures of Alpine Ibex that climb up its steep downstream face in order to lick salt off the stones. A video shared by the BBC's Forces of Nature with Brian Cox has been viewed over 208 million times as of May 2022. Despite the picturesque setting, Atlas Obscura describes the dam as "otherwise unremarkable." (Full article...)
The 263 mio. SR contract to build the dam was awarded to Yuksel Insaat Saudia Co Ltd., a subsidiary of the Turkish company Yüksel Holding AŞ. Work on the dam began in 2004. The dam was completed in April 2010.
Placement of the dam embankment began in August 1962, and on December 7, 1963, the dam was topped off. The diversion tunnels were closed and the reservoir began to fill on June 15, 1964. (Full article...)
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Imatra is a town in Finland, located in the southeastern interior of the country. Imatra is located in the region of South Karelia, on Lake Saimaa, the River Vuoksi. The population of Imatra is approximately Expression error: Unrecognized punctuation character ""., while the sub-region has a population of approximately 37,000. It is the th most populous municipality in Finland.
Imatra lies on the border with Russia. On the other side of the border, seven kilometres (4.3 mi) away from the centre of Imatra, lies the Russian town of Svetogorsk. The city of St. Petersburg is situated 210 km (130 mi) to the southeast, the Finnish capital Helsinki is 230 km (140 mi) away and Lappeenranta, the nearest Finnish town, is 37 km (23 mi) away.
The main employers are the pulp and paper manufacturer Stora Enso Oyj, the town of Imatra, the engineering steel manufacturer Ovako Bar Oy Ab and the Finnish Border Guard. , the total number of employees was 12,423. , 1,868 people were employed by the City of Imatra. The town's nicknames include Imis, Ibiza and Nahkalippis City (leather baseball cap city). Due to its location close to the border, Russian tourists are a common sight in the town, and Russian tourism is a boon to the local economy. Most people shop in Imatra, and Imatra's tax-free sales are the third largest among Finnish cities (only Helsinki and Lappeenranta are ahead).
The name of Imatra is thought to derive from a pre-Finno-Ugric language. The lightning symbols on Imatra's coat of arms refer to the power plants that were built in the early 1920s at the Tainionskoski and Imatrankoski rapids. The coat of arms was designed by Olof Eriksson [fi] and approved by the Imatra Town Council on 9 August 1950. The Ministry of the Interior approved the coat of arms for use on 25 October of the same year. (Full article...)
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The Reventazón Dam is a concrete-face rock-fill dam on the Reventazón River about 8 km (5.0 mi) southwest of Siquirres in Limón Province, Costa Rica. It was inaugurated on 16 September 2016, and its primary purpose is the production of hydroelectric power. The US$1.4 billion project and largest power station in the country has an installed capacity of 305.5 MW and is expected to provide power for 525,000 homes. Construction on the dam began in 2009. At a height of 130 metres (430 ft) and with a structural volume of 9,000,000 m3 (12,000,000 cu yd), it is the largest dam in Central America. To produce electricity, water from the reservoir is diverted about 3 km (1.9 mi) to the northeast where it reaches the power station along the Reventazón River. Due to its environmental features, like offset habitats and migration corridors for jaguars and many other species, the project could be a model for other future hydroelectric power plants. (Full article...)
Completed in 1986, the power station consists of four turbines of French origin with a nominal capacity of 150 MW each, totalling the installed capacity to 600 MW. (Full article...)
The 4,860-meter (15,940 ft) wide and 36.5-meter (120 ft) high dam is earth-filled with an impervious core. The storage capacity is 785 million m3 of water at normal water level, with a maximum capacity of 960 million m3. The dam also supplies about 6.7 MW of hydro-electric power. (Full article...)
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Gajah Mungkur Reservoir (Dam) (Indonesian: Waduk Gajah Mungkur) is a water reservoir located at Pokohkidul in the Wonogiri Regency, Central Java, of Indonesia. It was constructed by redirecting the Bengawan Solo River, the longest in the Java Islands, which originates from The Gajah Mungkur Mountain. The maximum inundation area of Gajah Mungkur Reservoir is 8,800 hectares and covers the seven subdistricts of Wonogiri, Ngadirojo, Nguntoronadi, Baturetno, Giriwoyo, Eromoko, and Wuryantoro.
The reservoir is used for irrigation, hydroelectric power, source of drinking water, tourism, aquaculture, and fisheries. Various fish may be found in the water, including parrotfish, wader pari, tawes, and patin jambal. (Full article...)
The Bongolo Dam is a dam on the Louetsi River in southwestern Gabon, near Bongolo. The dam was built in the early 1990s with Canadian investment. In 2020, it was announced that the dam was going to be refurbished by Société d’énergie et d’eau du Gabon, with five faulty turbines being replaced and the renewal of the safety and security equipment. (Full article...)
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The Rusumo Hydroelectric Power Station (Kinyarwanda: Urugomero rw'amashanyarazi rwa Rusumo, French: Centrale hydroélectrique de Rusumo), also known as the Rusumo Power Station, is a hydropower plant under construction, with initial planned capacity installation of 80 megawatts (110,000 hp) when completed. The project will involve the construction of a dam, with run of river design. A more expensive 90 megawatts (120,000 hp) reservoir design was considered before being abandoned in favor of an 80 MW project with a smaller environmental impact and an estimated cost of US$300 million compared to US$400 million for the bigger project. The World Bank announced on 6 August 2013 that it had approved loans totaling US$340 million towards the US$468.60 million needed for the project. In November 2013, the African Development Bank approved a loan of US$113 million towards completion of the project. (Full article...)
The Pulangi IV Hydroelectric Power Plant, also known as the Pulangi Dam, is located on the Pulangi River near Maramag in Bukidnon province on the island of Mindanao in the Philippines. It uses two reservoirs, produced by damming the Pulangi River, to supply water to a run-of-the-riverhydroelectric power plant; the power plant is capable of generating 255 megawatts (342,000 hp) of power. Construction began in 1982; the first two generators became operational in December 1985, with the last generator being commissioned in 1986.
The upper (pondage) reservoir located at diverts water into a power channel which parallels the river until it reaches the lower reservoir (surge pool) at , 7.5 km (5 mi) to the south. At the lower reservoir, water is fed to each of the three 85 MW (114,000 hp) Francis turbine-generators via a penstock. The Pulangi IV power plant provides 23% of the hydroelectric power generated on Mindanao.
Since operation, the reservoirs associated with the power plant have received an estimated 1,500,000 m3 (1,216 acre⋅ft) of sediment annually. Of the reservoir's combined 67,000,000 m3 (54,318 acre⋅ft) active capacity, 23,000,000 m3 (18,646 acre⋅ft) has been filled with silt. The siltation rate was almost 1 meter annually and caused the dam's reservoir to work at 50% capacity. The unexpected siltation threatens safe operation of the dams and power generation, in addition to drastically shortening the predicted operational lifespan of the dam. At first, the minimum and maximum water levels were raised and, in 2007, dredging work was performed around the head work of the upper reservoir's head. Selective dredging in the upper reservoir began in 2010, and continues as of 2011.
The Agua del Toro Dam is an arch dam on the Diamante River about 63 kilometres (39 mi) west of San Rafael in Mendoza Province, Argentina. The primary purpose of the dam is hydroelectric power generation and it supports a 150 megawatts (200,000 hp) power station located downstream. Construction on the dam began in 1966, and it was completed in 1973. The power station was started the same year and commissioned in 1982. The dam and power station is part of the Rio Diamante System which is owned jointly by Hidroeléctrica Diamante (HIDISA) and Hidroeléctrica de los Nihuiles (HINISA). (Full article...)
Poulaphouca Reservoir, officially Pollaphuca (from IrishPoll a' Phúca, meaning 'the Púca's hole'), is an active reservoir (for both water supply and electricity generation) and area of wild bird conservation in west County Wicklow, Ireland named after the Poulaphouca waterfall on its south-western end where the water exits the lake. The lake is also commonly known as the Blessington Lakes, even though there is just one.
It holds 166 billion litres (43.8 billion gallons, or 0.2 cubic km) and has a surface area 22.26 km2, making it the largest artificial reservoir in Ireland by capacity and surface area. It has a 44.3 km (27.5-mile) shoreline, and is 39.6 km (24.6 miles) from the sea. (Full article...)
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The El Chocón Dam (Spanish: Represa El Chocón Cerros Colorados) is the fourth of the five dams on the Limay River in the northwestern ArgentinePatagonia (the Comahue region), at 381 metres (1,250 ft) above mean sea level. El Chocón Cerros Colorados is on the Limay River at about 80 km (50 mi) upstream of its confluence with the Neuquén River.
El Chocón Cerros Colorados is used to regulate the flow of the Limay River, for irrigation, and for the generation of hydroelectricity. Its power station is the largest hydroelectric power plant in Patagonia, with a capacity of 1,260 megawatts (1,690,000 hp). It was built by the state-owned company Hidronor (Hidroeléctrica Norpatagónica). It started operating in 1973 and achieved full capacity in 1978. In the period 1974–1995, it produced an annual average of 2,700 gigawatt-hours (9,700 TJ). In 1993 it was privatized, with an exploitation concession granted to Hidroeléctrica El Chocón S. A.
While the formal name of the project is Embalse Ezequiel Ramos Mexía, in common use it ended up acquiring the name of the settlement that served as the construction's base of operations, Villa El Chocón (a small town, population 957, as of 2001).
El Chocón is part of a larger engineering scheme that also includes the Cerros Colorados Complex, on the Neuquén River. The Hydroelectric Complex which holds El Chocón and Arroyito Hydroelectric Power Plants, is located in the region known as Comahue, which is formed by the Argentine provinces of Río Negro and Neuquén and the southern area of the Buenos Aires and La Pampa provinces. (Full article...)
It has a total installed capacity of 960 MW, with 4 units each 160 MW and one unit at 320 MW, all equipped with francis turbines. With an annual production of approximately 3800 GWh, it is the largest power station in Norway with respect to annual production (in 2006). It is near the landing point of the 1,400 MW NORD.LINK power cable to Germany.
The powerstation utilises the waterfalls in the Sira and the Kvina river system, with a total height of 440 metres (1,440 ft). An application for an expansion with an additional 960 MW (pumped storage) was sent in 2008. The application is still pending. (Full article...)
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Lake Chivero is a reservoir on the Manyame River in Zimbabwe. It was formerly called Lake McIlwaine in memory of Sir Robert McIlwaine, a former judge of the High Court and founder of Southern Rhodesia's (later Rhodesia's, now Zimbabwe's) soil and water conservation movement.
Located southwest of Harare, it provides the main water supply for the city. The lake was constructed over two-and-a-half years and opened to the public in 1952. The dam wall is 400 metres long.
The water is also used for irrigation purposes and commercial fishing. Some of the fishes that are found in the lake include common grass carp, tigerfish, black bream, Clarias gariepinus, yellowfish, and green-headed bream.
The lake and hinterland are protected as part of Lake Chivero Recreational Park. The lake was designated a Ramsar wetland of international importance on 3 January 2013.
Remembrance Island is a small island in the reservoir. (Full article...)
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The Osborne Dam site on the Odzi River, Zimbabwe, was identified in the 1950s by the planning engineers of the Ministry of Water. Cored drilling investigations on the two possible alignments were completed in the 1960s. After the completion of Mazvikadei dam [1985–'88] with Italian financial aid, further funding became available for the project and when the 10 000 hectares of potential irrigable land was identified downstream the project was approved in 1989 by the multi-ministry irrigation committee of the Zimbabwe Government. (Full article...)
However it is also widely thought that the dam is to protect against the perceived North Korea / South Korea threat. South Korea also built two of its own dams in the area in the early 2010s. (Full article...)
The Quebrada de Ullúm Dam, or simply Ullúm Dam, is an embankment dam on the San Juan River, just west of San Juan in Ullúm Department of the Province of San Juan, Argentina. It is located at the gorge of the Quebrada de Ullum, 18 kilometres (11 mi) upstream from the provincial capital San Juan, and creates a reservoir with an area of 32 square kilometres (12 sq mi), a volume of 440 million cubic metres (16×10^9 cu ft), and average and maximum depths of 15 and 40 metres (49 and 131 ft), respectively. The reservoir feeds a hydroelectricpower station with an installed power capacity of 45 megawatts (60,000 hp).
The region is arid, with mean annual rainfall below 85 millimetres (3.3 in), and is traversed by the rivers, San Juan and Jáchal. The dam is employed to regulate the flow to irrigate about 800 square kilometres (310 sq mi) of the Tulum Valley for agriculture, which is the basis of the economy of San Juan. It also allows for recreational and tourist activities.
Work on the dam began in 1969, and the facility was inaugurated on December 3, 1980. (Full article...)
The West Seti Dam is a proposed hydroelectric dam on the Seti River in the Far-Western Development Region of Nepal. The power station would be located approximately 63 kilometres (39 mi) upstream of the Seti River confluence with the Karnali River, with the dam site located a further 19.2 kilometres (11.9 mi) upstream. All project sites, excluding the reservoir area and transmission line corridor, are located in either Doti and/or Dadeldhura Districts. The reservoir area is located in Doti, Dadeldhura, Baitadi and Bajhang Districts. The transmission line corridor is located in Doti, Dadeldhura, Kailali and Kanchanpur districts. (Full article...)
The Yaté Dam is an arch dam on the Yaté River in Yaté commune of New Caledonia, France. The primary purpose of the dam is hydroelectric power generation and it supports a 68 MW power station. Plans for the project began in the early 1950s and the dam was designed by Coyne et Bellier. The owner and operator of the project, New Caledonian Society Energy (ENERCAL), was established on 27 August 1955 to implement the project. Construction began that year and the power station was commissioned in 1958. The dam and entire scheme was inaugurated by Jacques Soustelle, then Minister of State in charge of Overseas Departments, on 21 September 1959. It is the tallest dam and creates the largest reservoir in New Caledonia.
While the main retaining portion of the dam is an arch design, it also has a concrete gravity section and an earthen and rock-fill section. The arch dam has a height of 60 m (200 ft) and length of 200 m (660 ft). On its left side adjoins the gravity section which serves as a spillway and is 61 m (200 ft) tall. It is 100 m (330 ft) long. The embankment section located direct the northwest of the gravity portion is 280 m (920 ft) long. Water from the dam is diverted through the hillsides via two 2,600 m (8,500 ft) long penstocks to the power station downstream along the Yaté River in the town of Yaté. The difference in elevation between the dam and power station affords a hydraulic head (water drop) of 157 m (515 ft). Within the power station lies four 17 MW Francis turbine-generates which produce an average of 307 GWh annually. (Full article...)
Mengkuang Dam is a dam in Central Seberang Perai District, Penang, Malaysia. It is the only dam situated in Seberang Perai (Penang Mainland) and the second dam built in Penang after Ayer Itam dam. It was officially opened by the former governor, Dr. Tun Awang bin Hassan in 1985. It has the water catchment area of 3.9 km2 (1.5 sq mi) and a gross storage capacity of 23.6 billion litres (5.2×109 imp gal; 6.2×109 US gal), making it the largest dam in Penang, almost 10 times the capacity of the Ayer Itam Dam. Mengkuang Dam closed to the public from August 1, 2011, until July 31, 2016, for enlargement and renovation. The US$200 million enlargement includes increasing the height of the dam by 11 m (36 ft) and its length 1.7 km (1.1 mi) to the west. A new intake and spillway will also be added. (Full article...)
{{ Transclude list item excerpts as random slideshow | List of mountain ranges | section=Mountain ranges on Earth }} Select from Earth section, avoiding Moon
Referred to as the world's smallest mountain range, the Sutter Buttes have as their highest point the summit of South Butte, at 2,122 ft (647 m), which is also the highest point in Sutter County.
The Britannia Range is a small mountain range of the Coast Mountains that runs along the eastern shore of Howe Sound just north of Vancouver, British Columbia, Canada. It is a subrange of the Pacific Ranges and often considered part of the North Shore Mountains. The range is bounded by the Howe Sound to the west, the Stawamus River to the north, Loch Lomond on the upper Seymour River to the east, and Deeks Lake to the south. However, some official maps extend the range further south of these boundaries and many local sources such as hiking guidebooks will often include all of the peaks along the Howe Sound between Deeks Lake and Cypress Mountain as part of the range.
The geology of the Britannia Range is different to the surrounding highly granitic North Shore Mountains due to the high prevalence of volcanic rock (such as at Watts Point volcanic centre) and sedimentary rock like sandstone and shale.
The Central Range is a mountain range on the island of Trinidad. It extends diagonally across the island and is a low-lying range rising from swampy areas into rolling hills. The tallest hills in the range are Mount Tamana (307 m), Mount Harris and Brigand Hill; all located in the northeastern portion of the range. The Central Range mountains are biodiverse, and are home to the Tamana Caves - the site of Trinidad's largest bat roost. Howler monkeys can be found here and numerous species of birds as well.
There are numerous streams and clean springs that flow from the Central Range. However there are few waterfalls. The most prominent of these falls are the Brasso Venado falls in Brasso Venado, and Gran Couva falls, or Carmelita falls, located in Gran Couva. To the north of the range are the Northern Lowlands (East–West Corridor and Caroni Plain). (Full article...)
Sredna Gora (Bulgarian: Средна гора[ˈsrɛdnɐɡoˈra]) is a mountain range in central Bulgaria, situated south of and parallel to the Balkan Mountains and extending from the river Iskar to the west and the elbow of river Tundzha north of the city of Yambol to the east. Sredna Gora is 285 km long, reaching 50 km at its greatest width. Its highest peak is Golyam Bogdan at 1,604 m (5,262 ft). It is part of the Srednogorie mountain chain system, which extends longitudinally across the most country from west to east, between the Balkan Mountains and the Sub-Balkan valleys to the north and the Kraishte, Rila and the Upper Thracian Plain to the south.
The mountain is divided into three parts by the rivers Topolnitsa and Stryama — Ihtimanska Sredna Gora to the west, Sashtinska Sredna Gora in the center, and Sarnena Sredna Gora to the east. Compared to most other mountain ranges in Bulgaria, Sredna Gora has lower average altitude, which determines higher temperatures and lower precipitation. There is an abundance of mineral springs all over Sredna Gora with many spa resorts, such as Hisarya, Starozagorski bani, Pavel Banya, etc. Sredna Gora is rich in mineral resources and especially copper. The economy is well developed. The region is an important national hub of copper extraction and processing industry, as well as of optical industry, both centered in and around the town of Panagyurishte. The largest city in Sredna Gora is Stara Zagora, one of the biggest economic centers of Bulgaria.
Sredna Gora has been continuously inhabited for thousands of years. In the 5th millennium BC it was largest mining center in Europe, extracting significant amounts of copper. The mountain range was among the centers of the ancient Thracian civilization, with numerous burial and cult remains being preserved from that period. The renown Thracian Panagyurishte Treasure has been discovered in Sredna Gora. In the Middle Ages the mountain range was part of the Bulgarian Empire since the early 8th century until it was conquered by the Ottoman Turks during the Bulgarian–Ottoman wars in the late 14th century. During the Ottoman rule Sredna Gora was an important center of resistance and the Bulgarian National Revival. It was the focal point of the April Uprising of 1876. Although many settlements in the region were destroyed in the aftermath of the rebellion, it had a decisive role for the subsequent Liberation of Bulgaria in 1878. (Full article...)
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A mid-ocean ridge (MOR) is a seafloor mountain system formed by plate tectonics. It typically has a depth of about 2,600 meters (8,500 ft) and rises about 2,000 meters (6,600 ft) above the deepest portion of an ocean basin. This feature is where seafloor spreading takes place along a divergent plate boundary. The rate of seafloor spreading determines the morphology of the crest of the mid-ocean ridge and its width in an ocean basin.
The production of new seafloor and oceanic lithosphere results from mantle upwelling in response to plate separation. The melt rises as magma at the linear weakness between the separating plates, and emerges as lava, creating new oceanic crust and lithosphere upon cooling.
The first discovered mid-ocean ridge was the Mid-Atlantic Ridge, which is a spreading center that bisects the North and South Atlantic basins; hence the origin of the name 'mid-ocean ridge'. Most oceanic spreading centers are not in the middle of their hosting ocean basis but regardless, are traditionally called mid-ocean ridges. Mid-ocean ridges around the globe are linked by plate tectonic boundaries and the trace of the ridges across the ocean floor appears similar to the seam of a baseball. The mid-ocean ridge system thus is the longest mountain range on Earth, reaching about 65,000 km (40,000 mi). (Full article...)
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The John Long Mountains, el. 7,923 feet (2,415 m), is a small mountain range northwest of Philipsburg, Montana in Granite County, Montana. The Beaverhead-Deerlodge National Forest and Lolo National Forest manage these mountains. A sizable roadless area of about 65,000 acres existed, as of 1990, in the John Long Mountains, centered on Silver King Mountain in the southern part of the range. It's unknown whether and to what extent this area's size has been reduced by logging. Lightly used trails traverse whitebark pine forests on the higher ridges, and forests of lodgepole pine, Douglas-fir, and heavy downfall on the eastern slopes. The western slopes have groves of douglas-fir amidst extensive grassy parks. Silver King Mountain is 7,581'.
The Babcock Mountain Bighorn Sheep Viewing Area, on the Rock Creek Road along the western edge of the John Longs, is an 8,000-acre area on the Lolo National Forest where bighorn sheep are commonly seen. Parking and hiking trails are provided.
There is some dispute as to whether the Quigg Peak roadless area, described in the Sapphire Mountains article, is really part of the John Long Mountains. If the Quigg Peak area is truly part of the John Long Mountains, then the highest point in the range would be Butte Cabin Ridge, el. 8,468'. (Full article...)
The range is surrounded by forests of coniferous trees and tundra plants. Rivers and creeks flow through its valleys, supplying the surrounding ecosystem with fresh water.
The mountains have historically been an important source of minerals to the Iñupiaq people. Pre-contact, jade was one of the strongest materials available and was used in the making of a number of necessary items, including tools, weaponry, knives, and beads.
The Cairngorms (Scottish Gaelic: Am Monadh Ruadh) are a mountain range in the eastern Highlands of Scotland closely associated with the mountain Cairn Gorm. The Cairngorms became part of Scotland's second national park (the Cairngorms National Park) on 1 September 2003. Although the Cairngorms give their name to, and are at the heart of, the Cairngorms National Park, they only form one part of the national park, alongside other hill ranges such as the Angus Glens and the Monadhliath, and lower areas like Strathspey.
The Cairngorms consists of high plateaux at about 1,000–1,200 m (3,300–3,900 ft) above sea level, above which domed summits (the eroded stumps of once much higher mountains ) rise to around 1,300 m (4,300 ft). Many of the summits have tors, free-standing rock outcrops that stand on top of the boulder-strewn landscape. In places, the edges of the plateau form steep cliffs of granite and they are excellent for skiing, rock climbing and ice climbing. The Cairngorms form an arctic-alpine mountain environment, with tundra-like characteristics and long-lasting snow patches. This area is home to bird species such as ptarmigan, dotterel, snow bunting, curlew and red grouse, as well as mammals such as mountain hare. The plateau also supports Britain's only herd of reindeer (albeit semi-domesticated). Surrounding the central massif are many remnants of the Caledonian forest in straths and glens of the Rivers Spey and Dee. These forests support many species that are rare elsewhere in Britain, including red squirrels, pine marten, wood ants, Scottish crossbill, capercaillie and crested tit.
There are no glaciers, but snow can fall in any month of the year, and snow patches usually persist all summer; for snow and ice climbing, the area is the most dependable in Britain. The mountains are also popular for hill-walking, ski touring and climbing, and there are three alpine ski centres in the range, at Cairn Gorm, The Lecht and Glenshee.
The Pindus (also Pindos or Pindhos; Greek: Πίνδος, romanized: Píndos; Albanian: Pindet; Aromanian: Pindu) is a mountain range located in Northern Greece and Southern Albania. It is roughly 160 km (100 miles) long, with a maximum elevation of 2,637 metres (8652') (Mount Smolikas). Because it runs along the border of Thessaly and Epirus, the Pindus range is known colloquially as the spine of Greece. The mountain range stretches from near the Greek-Albanian border in southern Albania, entering the Epirus and Macedonia regions in northern Greece down to the north of the Peloponnese. Geologically, it is an extension of the Dinaric Alps, which dominate the western region of the Balkan Peninsula. (Full article...)
The Scandinavian Mountains or the Scandes is a mountain range that runs through the Scandinavian Peninsula. The western sides of the mountains drop precipitously into the North Sea and Norwegian Sea, forming the fjords of Norway, whereas to the northeast they gradually curve towards Finland. To the north they form the border between Norway and Sweden, reaching 2,000 metres (6,600 ft) high at the Arctic Circle. The mountain range just touches northwesternmost Finland but are scarcely more than hills at their northernmost extension at the North Cape (Nordkapp).
The mountains are relatively high for a range so young and are very steep in places; Galdhøpiggen in South Norway is the highest peak in mainland Northern Europe, at 2,469 metres (8,100 ft); Kebnekaise is the highest peak on the Swedish side, at 2,104 m (6,903 ft), whereas the slope of Halti is the highest point in Finland, at 1,324 m (4,344 ft), although the peak of Halti is situated in Norway.
The Highlands (Scots: the Hielands; Scottish Gaelic: a' Ghàidhealtachd[əˈɣɛːəl̪ˠt̪ʰəxk], lit.'the place of the Gaels') is a historical region of Scotland. Culturally, the Highlands and the Lowlands diverged from the Late Middle Ages into the modern period, when Lowland Scots language replaced Scottish Gaelic throughout most of the Lowlands. The term is also used for the area north and west of the Highland Boundary Fault, although the exact boundaries are not clearly defined, particularly to the east. The Great Glen divides the Grampian Mountains to the southeast from the Northwest Highlands. The Scottish Gaelic name of A' Ghàidhealtachd literally means "the place of the Gaels" and traditionally, from a Gaelic-speaking point of view, includes both the Western Isles and the Highlands.The area is very sparsely populated, with many mountain ranges dominating the region, and includes the highest mountain in the British Isles, Ben Nevis. During the 18th and early 19th centuries the population of the Highlands rose to around 300,000, but from c. 1841 and for the next 160 years, the natural increase in population was exceeded by emigration (mostly to Canada, the United States, Australia and New Zealand, and migration to the industrial cities of Scotland and England.) The area is now one of the most sparsely populated in Europe. At 9.1/km2 (24/sq mi) in 2012, the population density in the Highlands and Islands is less than one seventh of Scotland's as a whole.
The Rieserferner Group forms the southwesternmost part of the High Tauern, its foothills running towards the southwest as far as Bruneck in the Puster Valley. Its name is derived from the Rieserferner, a glacier on the northern flank between the Hochgall (highest summit in the range at 3,436 m s.l.m.) and the Schneebiger Nock (3,358 m s.l.m.).
The Rieserferner Group is rather small in comparison with other Alpine ranges. It is, however, popular with climbers and hikers due to its prominent and steep, partly glaciated summits. (Full article...)
The Vancouver Island Ranges, formerly called the Vancouver Island Mountains, are a series of mountain ranges extending along the length of Vancouver Island which has an area of 31,788 km2 (12,273 sq mi). The Vancouver Island Ranges comprise the central and largest part of the island. The Geological Survey of Canada refers to Vancouver Island, Haida Gwaii, and the Alaska Panhandle as the Insular Belt including the sea floor out to 100 km (62 mi) west of Vancouver Island. The Vancouver Island Ranges are a sub-range of the Insular Mountains. (Full article...)
Much of the forest cover is beech/podocarp with understory of a variety of ferns and shrubs; crown fern (Lomaria discolor) is one of the dominant understory ferns. (Full article...)
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The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as many of those in the North Cascades, and the notable volcanoes known as the High Cascades. The small part of the range in British Columbia is referred to as the Canadian Cascades or, locally, as the Cascade Mountains. The highest peak in the range is Mount Rainier in Washington at 14,411 feet (4,392 m). The Cascades are part of the Pacific Ocean's Ring of Fire, the ring of volcanoes and associated mountains around the Pacific Ocean. All of the eruptions in the contiguous United States over the last 200 years have been from Cascade volcanoes. The two most recent were Lassen Peak from 1914 to 1921 and a major eruption of Mount St. Helens in 1980. Minor eruptions of Mount St. Helens have also occurred since, most recently from 2004 to 2008. The Cascade Range is a part of the American Cordillera, a nearly continuous chain of mountain ranges (cordillera) that form the western "backbone" of North, Central, and South America.
The Serra Geral (General Mountains) is a mountain range in southern Brazil, constituting the southern portion of the Serra do Mar system which runs along Brazil's southeastern coast. The Serra Geral runs parallel to the Atlantic coast in Santa Catarina and northern Rio Grande do Sul states, separating a narrow coastal plain from an interior plateau. The coastal plain is characterized by short rivers and frequent lagoons and bays, and lies within the humid tropical Serra do Mar coastal forestsecoregion.
The plateau to the west of the range is drained by tributaries of the Uruguay River, including the Pelotas and Canoas, and by the Jacuí River and its tributaries, which drains south into the Lagoa dos Patos of Rio Grande do Sul.
The Cusuco National Park (Parque Nacional El Cusuco) is located on the Honduran side and protects an area spanning 23,440 hectares of temperate forest in the Merendón mountain range. The core zone is located at an altitude of 1,800 - 2,242 m. (15° 29.8' − 15° 32.1' N, 88° 13.0' − 88° 16.3' W). Predominant forest habitats in the park are cloud forests (1,500 - 2,242 m), semi-arid pine forests on south-facing slopes (800 - 1,500 m), and wet deciduous forests on north-facing slopes (500 - 1,500 m). (Full article...)
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The Metacomet Ridge, Metacomet Ridge Mountains, or Metacomet Range of southern New England is a narrow and steep fault-block mountain ridge known for its extensive cliff faces, scenic vistas, microclimate ecosystems, and rare or endangered plants. The ridge is an important recreation resource located within 10 miles (16 km) of more than 1.5 million people, offering four long-distance hiking trails and over a dozen parks and recreation areas, including several historic sites. It has been the focus of ongoing conservation efforts because of its natural, historic, and recreational value, involving municipal, state, and national agencies and nearly two dozen non-profit organizations.
The Metacomet Ridge extends from Branford, Connecticut, on Long Island Sound, through the Connecticut River Valley region of Massachusetts, to northern Franklin County, Massachusetts, 2 miles (3 km) short of the Vermont and New Hampshire borders for a distance of 100 miles (160 km). It is geologically distinct from the nearby Appalachian Mountains and surrounding uplands, and is composed of volcanic basalt (also known as trap rock) and sedimentary rock in faulted and tilted layers many hundreds of feet thick. In most cases, the basalt layers are dominant, prevalent, and exposed. The ridge rises dramatically from much lower valley elevations, although only 1,200 feet (370 m) above sea level at its highest, with an average summit elevation of 725 feet (221 m). (Full article...)
Herangi is in the Maniapotorohe. Pā and other archaeological sites are found close together along the coast, but very few in the range itself. The Kiritehere valley was settled in the 1900s, but much of the rest of the range is in Whareorino Conservation Area, of particular importance for its native frogs.
A Reims Cessna F152 II crashed into a tree on a ridge between Whareorino (649 m (2,129 ft)) and Mangatoa Saddle on 21 July 2009. The pilot, who died, was inexperienced and had not complied with requirements to calculate a route allowing for the poor weather. (Full article...)
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The Black Mountains are a mountain range in western North Carolina, in the southeastern United States. They are part of the Blue Ridge Province of the Southern Appalachian Mountains. The Black Mountains are the highest mountains in the Eastern United States. The range takes its name from the dark appearance of the red spruce and Fraser fir trees that form a spruce-fir forest on the upper slopes which contrasts with the brown (during winter) or lighter green (during the growing season) appearance of the deciduous trees at lower elevations. The Eastern Continental Divide, which runs along the eastern Blue Ridge crest, intersects the southern tip of the Black Mountain range.
The Eastern Romanian (Oriental) Carpathians include:
Ridges of Bukovina (RO: Obcinele Bucovinei), i.e. Obcina Mare (Great Ridge), Obcina Mestecăniș (Mestecăniș Ridge) and Obcina Feredeului (Feredeu Ridge). In Romania these are considered part of the northern Carpathians of Maramureș and Bukovina (Munții Carpați ai Maramureșului și Bucovinei)
Stânișoara Mountains (RO: Munții Stânișoarei). In Romania considered part of the central Carpathians of Moldavia and Transylvania (Munții Carpați Moldo-Transilvani), or "MMT"
The Sayan Mountains' towering peaks and cool lakes southwest of Tuva give rise to the tributaries that merge to become one of Siberia's major rivers, the Yenisei River, which flows north over 3,400 kilometres (2000 mi) to the Arctic Ocean. This is a protected and isolated area, having been kept closed by the Soviet Union since 1944. (Full article...)
The range is drained by the Waitakaruru and Whangamarino Rivers and their tributaries at the north end. Further south, tributaries of the Piako River drain the east side of the range and streams flow to the Waikato on the west.
The Tapuae-o-Uenuku / Hector Mountains are a mountain range in the New Zealand region of Otago, near the resort town of Queenstown and just south of the more famous Remarkables. For most of its length, the mountains run adjacent to the southern reaches of Lake Wakatipu, before extending approximately 14 kilometres (8.7 mi) further south, past the glacial moraine at Kingston on the southern end of the lake. On their eastern side, the mountains mark the edge of the Nevis valley, a largely tussocked area which saw significant activity during the Otago Gold Rush of the 1860s. Historically, the mountains were an important mahinga kai (food gathering-place) for Ngāi Tahu and other local Māoriiwi, who used the area to hunt for weka and gather tikumu while visiting the region.
Many of the peaks in the range remain unnamed, a group which – until 2013 – included its highest point. Following a joint process between Ngāi Tahu and the Central Otago District Council, four new names were added to the region in 2013, including the adoption of the range's current dual name. This included the name of Mount Tūwhakarōria for the highest point of the range, as well as Te Karearea Peak for another prominent point as seen from Cromwell and Lake Te Kōhua for the small lake between the two. (Full article...)
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The Old Man Range, also called Kopuwai, is a mountain range in Central Otago, in the South Island of New Zealand. It lies to the west of the valley of the Clutha River, close to the town of Alexandra and the artificial Lake Roxburgh. The range stretches north-south for a distance of some 40 kilometres (25 mi). Part of the range forms the border between the Otago and Southland Regions. The range's Māori name, Kopuwai, means "Water Swallower", and was the name of a mythical giant who lived in the area.
The range rises to a narrow ridge at a height of just over 1,500 metres (4,900 ft). The highest points are the 1,682 metres (5,518 ft) Obelisk (also known as The Old Man, and from which the range gets its name) at (), and Hyde Rock (1,673 metres (5,489 ft)). The eastern flanks of the range are steep, falling away to the Clutha Valley. In contrast, the western flanks fall gently to a high plateau before rising to a lower ridge known as the Old Woman Range. The plateau which has areas of both bare rock and marsh, is the source of numerous creeks, most of them part of the catchment of the young Waikaia and Earnscleugh Rivers.
The geology of the range is dominated by the schists of the Caples and Torlesse Terranes. The rock is a source of gold, and the area was worked during the Otago Gold Rush of the 1860s. Several remnants of the mining era can still be seen in the range.
Much of the range is conservation land controlled by the New Zealand Department of Conservation (DOC), and divided between the Kopuwai and Bain Block Conservation Areas.
Two more, much smaller, ranges of this name exist in New Zealand — a low range of hills in inland Canterbury, between Lakes Pukaki and Alexandrina, and a higher hill range in the Tasman District, close to Farewell Spit. (Full article...)
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The Henry Mountains is a mountain range located in the southeastern portion of the U.S. state of Utah that runs in a generally north-south direction, extending over a distance of about 30 miles (48 km). They were named by Almon Thompson in honor of Joseph Henry, the first secretary of the Smithsonian Institution. The nearest town of any size is Hanksville, Utah, which is north of the mountains. The Henry Mountains were the last mountain range to be added to the map of the 48 contiguous U.S. states (1872), and before their official naming by Thompson were sometimes referred to as the "Unknown Mountains." In Navajo, the range is still referred to as Dził Bizhiʼ Ádiní ("mountain whose name is missing").
The name for the mountain ranger was first proposed by then University of Wisconsin geologist, Eliot Blackwelder. It is named after A. J. Brabazon, who created the first topographic map of the ranger in 1895. (Full article...)
Upper parties of Bieszczady are covered with montane meadows called polonyna (Ukrainian: полонина; Polish: połonina; Slovak: polonina). (Full article...)
The name shows the range's great importance as a source of drinking water, and the waters supply a great number of important cities in the southeast of Brazil. From its brooks are formed the Jaguari River, which supplies the northern region of Greater São Paulo; most left-bank tributaries of the Paraíba do Sul River, which crosses a densely populated and highly industrialized region; and the Grande River, which is the source of the Paraná River, one of the longest and most important in South America and the river with the world's largest hydroelectric output, through a series of power plants way down the river to Argentina and Paraguay.
{{ Transclude list item excerpts as random slideshow | List of dams and reservoirs | section=Africa | sectiononly=yes }} Should pick only the international dams
The Diama Dam, sometimes referred to as the Maka–Diama Dam (French: Barrage de Maka-Diama) is a gravity dam on the Senegal River, spanning the border of Senegal and Mauritania. It is located next to the town of Diama, Senegal and about 22 km (14 mi) north of Saint-Louis, Senegal. The purpose of the dam is to prevent saltwater intrusion upstream, supply water for the irrigation of about 45,000 ha (110,000 acres) of crops and create a road crossing for the road between St. Louis and Nouakchott in Mauritania. Additionally, a ship lock built within the dam provides for navigation upstream. Plans for the dam were first drawn in 1970 when the riparian states within the Senegal River Basin Development Authority agreed to develop the Senegal River. The Diama Dam was to be constructed in conjunction with the Manantali Dam which was to be located further upstream in Mali. Construction on the Diama Dam began on 15 September 1981 and was completed on 12 August 1986. The Manantali Dam was completed in 1988. The Diama project was funded by a US$149.5 million loan from the African Development Bank. The main section of the dam with ship lock and spillway is 170 m (560 ft) long while a 440 m (1,440 ft) long embankment dam section extends north to the edge of the river. A dike further extends the dam to the north. The dam is 18 m (59 ft) tall and its spillway has a maximum discharge of 6,500 m3/s (230,000 cu ft/s).
The small town of Diama is known as a border crossing to and from Mauritania, as the dam is the only land bridge between the two countries. (Full article...)
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The Tsiazompaniry Dam is a buttress dam on the Varahina-South River, a tributary of the Ikopa River, near Tsiazompaniry in the Analamanga Region of Madagascar. The dam was constructed by a French firm in 1956. It creates Lake Tsiazompaniry, the largest reservoir in the country, which has a surface area of 31 km2 (12 sq mi) and a storage volume of 260,000,000 m3 (210,000 acre⋅ft). A second buttress dam, 1 km (0.62 mi) northwest of the main dam helps withhold the reservoir. Water released from the dam supplies a regulated flow to hydroelectric power station at the Antelomita Dam downstream. Efforts to install a 5.25 MW power station at the base of the dam began in 2011. (Full article...)
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The Cahora Bassa Dam is located in Mozambique. It is one of two major dams on the Zambezi river, the other being the Kariba. The project began to come online in 1979 after much political debate. This dam uses the Zambezi River water to generate electricity by turning turbines. That energy is then sent to South Africa. The Cahora Bassa Dam forms Cahora Bassa Lake. The dam is jointly owned by Mozambique and Portugal. From independence until 2007, eighteen percent share of the dam and lake was owned by Mozambique and eighty-two percent by Portugal. Portugal sold down its share to 15 percent in 2007. The Cahora Bassa Dam is the largest hydroelectric power plant in southern Africa and the most efficient power generating station in Mozambique. (Full article...)
Its construction, at the cost of 140 million US dollars, was financed by several backers.
The dam has a crest length of 2,600 metres (8,500 ft) and a height of 23 metres (75 ft). With a power output of 44 MW, the dam has an energy output of 200 million kilowatt-hours per year. The dam provides Bamako, Kati, Koulikoro, Ségou, Fana, Dioïla, Yanfolila and Kalana with electricity. It was brought into service in 1982, and renovated between 1996 and 2001.
The retaining basin of the dam forms the artificialLake Sélingué. The water level has a maximum height of 349 metres (1,145 ft) but varies throughout the year. When full the lake stores 2.2 cubic kilometres (0.53 cu mi) of water and has an area of 409 square kilometres (158 sq mi). It allows agriculture on the irrigated perimeters, managed by the Office of Rural Development of Sélingué, as well as fishing. (Full article...)
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The Antelomita Hydroelectric Power Station is located in the rural commune Anjeva Gara of the Analamanga Region, Madagascar. The hydroelectric power station comprises two parts, Antelomita I and II. Both are adjacent to one another on separate water falls along the Ikopa River. Each water fall is dammed and water is diverted to the power station; each of which contains three 1.4 megawatts (1,900 hp) generators. The first two were commissioned in 1930, the second two in 1952 and the final two in 1953. Both stages have an installed capacity of 8.4 megawatts (11,300 hp). They were built by a French firm but are now owned and operated by Jirama. The Tsiazompaniry and Mantasoa Dams upstream regulate water to the power station.
The Aswan Dam, or more specifically since the 1980s, the Aswan High Dam, is one of the world's largest embankment dams, which was built across the Nile in Aswan, Egypt, between 1960 and 1970. When it was completed, it was the tallest earthen dam in the world, eclipsing the United States' Chatuge Dam. Its significance largely upstaged the previous Aswan Low Dam initially completed in 1902 downstream. Based on the success of the Low Dam, then at its maximum utilization, construction of the High Dam became a key objective of the new regime, the Free Officers movement of 1952; with its ability to better control flooding, provide increased water storage for irrigation and generate hydroelectricity, the dam was seen as pivotal to Egypt's planned industrialization. Like the earlier implementation, the High Dam has had a significant effect on the economy and culture of Egypt.
Before the High Dam was built, even with the old dam in place, the annual flooding of the Nile during late summer had continued to pass largely unimpeded down the valley from its East Africandrainage basin. These floods brought high water with natural nutrients and minerals that annually enriched the fertile soil along its floodplain and delta; this predictability had made the Nile valley ideal for farming since ancient times. However, this natural flooding varied, since high-water years could destroy the whole crop, while low-water years could create widespread drought and consequently famine. Both these events had continued to occur periodically. As Egypt's population grew and technology increased, both a desire and the ability developed to completely control the flooding, and thus both protect and support farmland and its economically important cotton crop. With the greatly increased reservoir storage provided by the High Aswan Dam, the floods could be controlled and the water could be stored for later release over multiple years.
The Aswan Dam was designed by Nikolai Aleksandrovich Malyshev of the Moscow-based Hydroproject Institute. Designed for both irrigation and power generation, the dam incorporates a number of relatively new features, including a very deep grout curtain below its base. Although the reservoir will eventually silt in, even the most conservative estimates indicate the dam will give at least 200 years of service. (Full article...)
The Gove Dam is an embankment dam on the Kunene River about 75 km (47 mi) south of Huambo in Huambo Province, Angola. The purpose of the dam is to control floods and generate hydroelectric power. It has a power generating capacity of 60 megawatts (80,000 hp) each) (three turbines of 20 megawatts (27,000 hp) each), enough to power over 30,000 homes. (Full article...)
The Al Massira Dam is a gravity dam located 70 kilometres (43 mi) south of Settat on the Oum Er-Rbia River in Settat Province, Morocco. Completed in 1979, the dam provides water for the irrigation of over 100,000 hectares (250,000 acres) of farmland in the Doukkala region. The dam's hydroelectric power plant also generates 221 gigawatt-hours (800 TJ) on average annually. The power station was commissioned in 1980. Just north of the dam is a rip rap saddle dam that supports water elevation in the reservoir. The dam's reservoir and wetlands were designated as a Ramsar site in 2005.
In 2024 analysis of satellite images of the dam by the BBC revealed the volume of water was 3% of the amount present nine years previously. The country had suffered from six consecutive years of drought. The Moroccan water ministry told the BBC that use of the dam's water for irrigating farmland had been suspended since 2021, the water being reserved for supplying cities such as Casablanca and Marrakesh. Many of the springs in the Middle Atlas mountains, which feed the reservoir, had dried-up. Reduced snowfall at higher altitude had also contributed to less meltwater flowing into the streams feeding the dam. In August 2023 Morocco recorded a record highest-ever temperature of 50.4C which caused an increase in evaporation, adding to a reduction in water's level. (Full article...)
Hombolo Dam is a dam in Tanzania. It is at Hombolo-Bwawani village, in Dodoma-rural District. The dam was constructed by the colonial government in 1957 for irrigation, domestic water supply, and water for livestock. (Full article...)
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The Osborne Dam site on the Odzi River, Zimbabwe, was identified in the 1950s by the planning engineers of the Ministry of Water. Cored drilling investigations on the two possible alignments were completed in the 1960s. After the completion of Mazvikadei dam [1985–'88] with Italian financial aid, further funding became available for the project and when the 10 000 hectares of potential irrigable land was identified downstream the project was approved in 1989 by the multi-ministry irrigation committee of the Zimbabwe Government. (Full article...)
The Lom Pangar Dam is an embankment dam with a center gravity dam section currently under construction on the Lom River about 88 kilometres (55 mi) north of Bertoua in the East Region of Cameroon. It is located about 4 kilometres (2.5 mi) downstream of the Lom River's confluence with the Pangar River and about 13 kilometres (8.1 mi) upstream of where the Lom joins the Sanaga River. The dam's purpose is to produce hydroelectric power and regulate water flows along the Sanaga River. It is potentially part of a larger dam cascade on the Sanaga. (Full article...)
The Akosombo Dam, also known as the Volta Dam, is a hydroelectric dam on the Volta River in southeastern Ghana in the Akosombo gorge and part of the Volta River Authority. The construction of the dam flooded part of the Volta River Basin and led to the subsequent creation of Lake Volta. Lake Volta is the largest man-made lake in the world by surface area. It covers 8,502 square kilometres (3,283 sq mi), which is 3.6% of Ghana's land area. With a volume of 148 cubic kilometers, Lake Volta is the world's third largest man-made lake by volume; the largest being Lake Kariba which contains 185 cubic kilometers of water.
The primary purpose of the Akosombo Dam was to provide electricity for the aluminium industry. The Akosombo Dam was called "the largest single investment in the economic development plans of Ghana." The dam is significant for providing the majority of both Togo and Benin's electricity, although the construction of the Adjarala Dam (on Togo's Mono River) hopes to reduce these countries' reliance on imported electricity. The dam's original electrical output was 912 megawatts (1,223,000 hp), which was upgraded to 1,020 megawatts (1,370,000 hp) in a retrofit project that was completed in 2006.
The flooding that created the Lake Volta reservoir displaced many people and had a significant impact on the local environment, including seismic activity that led to coastal erosion; a changed hydrology caused microclimatic changes with less rain and higher temperatures. The soil surrounding the lake is less fertile than the soil under it, and heavy agricultural use has required the use of fertilizers, which in turn has led to eutrophication, which caused, among others, the explosive growth of an invasive weed that renders water navigation and transportation difficult, and form a habitat for the vectors of water-borne illnesses such as bilharzia, river blindness and malaria. Resettlement of the displaced inhabitants proved complex and in some cases unsuccessful; traditional farming practices disappeared and poverty increased. (Full article...)
An assessment of the dam's stability, taken out in the year 2004, revealed 19 stability and safety issues, mainly due to deferred maintenance. However, the main dam structure was in a stable condition at that time. (Full article...)
The Naute Dam is a dam outside of Keetmanshoop in the ǁKaras Region of Namibia. It was built by Concor between 1970 and 1972 and was officially commissioned in September 1972. It is the third largest dam in Namibia after Hardap Dam to Naute's north and can hold up to 69 million cubic metres of water. The dam's source is the Löwen River, a tributary of the Fish River. (Full article...)
The syndicate had originally approached veteran comic strip creators Milton Caniff and Noel Sickles about doing a Bruce Lee strip in 1978. The project never got off the ground, and five years later the syndicate tried again.
Intended for "downscale, . . . very young audiences", The Legend of Bruce Lee was intended to "help boost newspaper circulation by attracting younger or less well-educated readers who don't normally read newspapers". It was written by Sharman DiVono (who herself had martial arts training), and illustrated by Fran Matera (with uncredited assists from Dick Kulpa). (Full article...)
The version of the film that is commonly distributed in the West (USA) on public domain-type DVD and video labels runs 93 minutes in length. The British VHS-version released in 1979 runs 118 minutes. (Full article...)
Announced in July 2017, it is the first Tarantino film not to involve Bob and Harvey Weinstein, as Tarantino ended his partnership with the brothers following the sexual abuse allegations against the latter. After a bidding war, the film was distributed by Sony Pictures, which met Tarantino's demands including final cut privilege. Pitt, DiCaprio, Robbie, Zoë Bell, Kurt Russell, and others joined the cast between January and June 2018. Principal photography lasted from June through November around Los Angeles. Once Upon a Time in Hollywood is the final film to feature Luke Perry, who died on March 4, 2019, and it is dedicated to his memory.
Once Upon a Time in Hollywood premiered at the 2019 Cannes Film Festival on May 21, 2019, and was theatrically released in the United States on July 26, 2019, and in the United Kingdom on August 14. It grossed $374 million worldwide and received praise from critics for Tarantino's direction and screenplay, the performances (particularly from DiCaprio and Pitt), cinematography, soundtrack, sound design, costume design, and production values. The National Board of Review and the American Film Institute named Once Upon a Time in Hollywood one of the top-ten films of 2019. Once Upon a Time in Hollywood was nominated for ten awards at the 92nd Academy Awards, winning two, and received numerous other accolades. A novelization, written by Tarantino in his debut as an author, was published on June 29, 2021. (Full article...)
The Way of the Dragon was released in Hong Kong on 30 December 1972, and in the United States in August 1974. The film went on to gross an estimated US$130 million worldwide (equivalent to over $700 million adjusted for inflation), against a tight budget of $130,000, earning a thousand times its budget. It was the highest-grossing Hong Kong film up until Lee's next film Enter the Dragon (1973).
The film is primarily set in a restaurant in Rome. The owners are being harassed by a local crime boss, and request help from a relative in Hong Kong. The help arrives in the form of a young martial artist. The conflict between the restaurant staff and the gangsters soon escalates. (Full article...)
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The Dragon Lives (Chinese: 詠春大兄; pinyin: Yǒng Chūn Dà Xiōng; Jyutping: wing6 cheun1 daai6 hing1), also known as He's a Legend, He's a Hero, is a 1976 Hong Kong martial arts film starring Bruce Li and directed by Wang Hsing-lei (credited as Singloy Wang). A fictional account of Bruce Lee's life, it is one of numerous films which exploited the popularity of Lee after his death, a practice called Bruceploitation. The film was released in the United States by Film Ventures International on 19 September 1978.
In 2016, Magnetic Press published four issues of Bruce Lee: The Dragon Rises, co-written by Lee's daughter Shannon Lee and Jeff Kline, and illustrated by Brandon McKinney. The fictional story takes places in 2012 with Bruce Lee escaping from a science lab.
In 2018, Magnetic Press/Darby Pop Publishing released the one-shot Bruce Lee: The Walk Of The Dragon, also written by Shannon Lee. (Full article...)
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The Game of Death (Chinese: 死亡的遊戲) is an incomplete Hong Kong martial arts film, of which portions were filmed between September and October 1972, directed, written, produced by and starring Bruce Lee. The project was paused to film and produce Enter the Dragon. For The Game of Death, over 120 minutes of footage was shot, which was later misplaced in the Golden Harvest archives. The remaining footage has since been released with Lee's original Cantonese and English dialogue, with John Little dubbing Lee's Hai Tien character as part of the documentary titled Bruce Lee: A Warrior's Journey. Much of the footage that was shot is from what was to be the climax of the film.
During filming, Lee received an offer to star in Enter the Dragon, the first kung fu film to be produced by a Hollywood studio (Warner Bros.), and with a budget unprecedented for the genre ($850,000). Lee died of cerebral edema before the film's release. At the time of his death, he had made plans to resume the filming of The Game of Death. After Lee's death, Enter the Dragon director Robert Clouse was enlisted to finish the film using two stand-ins; it was released in 1978 as Game of Death, five years after Lee's death, by Golden Harvest.
The story of Lee's original 1972 film involves Lee's character, in order to save his younger sister and brother, joining a group of martial artists who are hired to retrieve a stolen Chinese national treasure[need quotation to verify] from the top floor of a five-story pagoda in South Korea, with each floor guarded by martial artists who must be defeated while ascending the tower.[additional citation(s) needed] The 1978 film's plot was altered to a revenge story, where the mafia attempts to kill Lee's character, who fakes his death and seeks vengeance against those who tried to kill him. The final part of the film uses some of Lee's original film footage, but with the pagoda setting changed to a restaurant building, where he fights martial artists hired by the mafia in an attempt to rescue his fiancée Ann Morris (played by Colleen Camp). This revised version received a mixed critical reception but was commercially successful, grossing an estimated US$50,000,000 (equivalent to $230,000,000 in 2023) worldwide. (Full article...)
Bruce Lee: The Lost Interview is the name given to the 9 December 1971 edition of The Pierre Berton Show, which featured martial artist/actor Bruce Lee in his only English speaking television interview. Its title is derived from its status; it was presumed lost for several years until its rediscovery and airing on 2 November 1994. Over the course of the interview, which was filmed in Hong Kong, Bruce Lee and Pierre Berton discuss Lee's career, various aspects of martial arts philosophy and the inherent problems faced by an Asian in pursuing stardom in Hollywood. A review of the interview by Bill Stockey said that Bruce Lee's "human side is exposed and he is portrayed as more approachable". (Full article...)
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Bruce Lai, real name Chang Yi-tao (1950 – 2014), was a Hong Kong actor who starred in many Godfrey Ho films.
Jeet Kune Do (Chinese: 截拳道; "way of the intercepting fist"; abbreviated JKD) is a hybrid martial art conceived and practiced by martial artist Bruce Lee. It was formed from Lee's experiences in unarmed fighting and self-defense—as well as eclectic, Zen Buddhist and Taoist philosophies—as a new school of martial arts thought.
The core of Jeet Kune Do is the interception of the opponent, making corresponding responses or counterattacks that strike at incoming attacks. JKD also incorporates a set of principles to help practitioners make instant decisions and improve the physical and mental self, being intended to have practical applications in life without the traditional routines and metaphysics of conventional martial arts. As an eclectic martial art, it relies on a fighting style heavily influenced by Wing Chun, Tai Chi, taekwondo, boxing, fencing and jujutsu.
Bruce Lee himself never formalized Jeet Kune Do before he died. This forced later JKD practitioners to rely upon their own interpretation of the philosophy created by Bruce Lee. (Full article...)
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Dragon Lee (born August 12, 1958) is an actor and practitioner of taekwondo and hapkido. He made a name for himself as a martial arts film star in the 1970s and 80s. His birth name is Moon Kyung-seok, but he is also called Keo Ryong (literally "giant dragon") in South Korea. (Full article...)
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41 Cumberland Road in 2008, operating at that time as a love hotel. 41 Cumberland Road is the address of Bruce Lee's former home in Kowloon Tong, Kowloon, Hong Kong, where he spent his last year with his family. The place was affectionately known as "the Crane's Nest".
Dragon: The Bruce Lee Story is a 1993 American biographicaldrama film directed by Rob Cohen. The film stars Jason Scott Lee, with a supporting cast including Lauren Holly, Nancy Kwan and Robert Wagner. The film follows the life of actor and martial artist Bruce Lee (Jason) from his relocation to the United States from Hong Kong to his career as a martial arts teacher, and then as a television and film actor. It also focuses on the relationship between Bruce and his wife Linda Lee Cadwell, and the racism to which Bruce was subjected.
The primary source of the screenplay is Cadwell's 1975 biography Bruce Lee: The Man Only I Knew. Other sources include Robert Clouse's book Bruce Lee: The Biography and research by Cohen, including interviews with Cadwell and Bruce's son, Brandon Lee. Rather than a traditional biographical film, Cohen decided to include elements of mysticism and to dramatise fight scenes to give it the same tone as the films in which Bruce starred. Dragon was filmed primarily in Hong Kong, Los Angeles and San Francisco.
Dragon: The Bruce Lee Story received generally positive reviews, with critics typically finding it entertaining despite criticisms of its veneration of Bruce. Jason was widely praised for his performance. The film was a commercial success and its revenue exceeded box office averages for biographical films, which was attributed to its romantic themes and its appeal to people outside the traditional kung fu film audience. A video game adaptation of the same name was released the following year. Dragon is dedicated to Brandon, who died several weeks before its release. (Full article...)
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Bruce Le (simplified Chinese: 吕小龙; traditional Chinese: 呂小龍; pinyin: Lǚ Xiǎolóng; born June 5, 1950) is a martial artist and actor known for his martial arts film of the 1970s and 1980s. Most of these were inexpensively produced and were made to capitalise on the martial arts phenomenon started by Bruce Lee, whose death in 1973 left a large box office void (hence the name change to "Bruce Le").
Bruce Lee's Fighting Method is a book of volumes covering Bruce Lee's martial arts abilities of the Jeet Kune Do movement. The book is available as a single hardcover volume or a series of four paperback volumes. The text describes Bruce Lee's Kung Fufighting techniques, philosophy and training methods. This book was originally written in 1966 by Bruce Lee. However, Lee decided not to publish this work as he feared that instructors would use the fighting knowledge in this text to promote themselves. In 1978, after Bruce Lee's death, his widow Linda Lee Cadwell decided to make available the information on her husband's work. Lee's death changed the perspective of releasing the information that Bruce Lee himself had vacillated about. The book was published with the help of Mitoshi Uyehara. Uyehara was the founder and owner of Black Belt Magazine. During the early years of the publication, Uyehara served as the publisher. Bruce Lee contributed many articles to the publication during the 1960s and a friendship ensued between the two men. Uyehara, a martial artist in his own right, was a key personage in arranging Lee's material for publication. (Full article...)
Bruce Lee is a platform game written by Ron J. Fortier for Atari 8-bit computers and published in 1984 by Datasoft. The graphics are by Kelly Day and music by John A. Fitzpatrick. The player takes the role of Bruce Lee, while a second player controls either Yamo or alternates with player one for control of Bruce Lee.
Commodore 64 and Apple II versions were released the same year. The game was converted to the ZX Spectrum and Amstrad CPC and published by U.S. Gold. It was the first U.S. Gold release featuring a famous individual. An MSX version was published in 1985 by Comptiq. (Full article...)
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Bruce Lee: A Dragon Story also known as The Bruce Lee Story, Super Dragon: The Bruce Lee Story and Bruce Lee Story: Super Dragon) is a 1974 Bruceploitation film starring Bruce Li. The film is a loose biopic about martial arts actor Bruce Lee and centers on his supposed affair with actress Betty Ting-Pei. The film is notable for being the first biopic of Bruce Lee (it was released the year following his death), the debut film of notorious Lee imitator Bruce Li, and the first film in the Bruceploitation genre. (Full article...)
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41 Cumberland Road in 2008, operating at that time as a love hotel. 41 Cumberland Road is the address of Bruce Lee's former home in Kowloon Tong, Kowloon, Hong Kong, where he spent his last year with his family. The place was affectionately known as "the Crane's Nest".
Announced in July 2017, it is the first Tarantino film not to involve Bob and Harvey Weinstein, as Tarantino ended his partnership with the brothers following the sexual abuse allegations against the latter. After a bidding war, the film was distributed by Sony Pictures, which met Tarantino's demands including final cut privilege. Pitt, DiCaprio, Robbie, Zoë Bell, Kurt Russell, and others joined the cast between January and June 2018. Principal photography lasted from June through November around Los Angeles. Once Upon a Time in Hollywood is the final film to feature Luke Perry, who died on March 4, 2019, and it is dedicated to his memory.
Once Upon a Time in Hollywood premiered at the 2019 Cannes Film Festival on May 21, 2019, and was theatrically released in the United States on July 26, 2019, and in the United Kingdom on August 14. It grossed $374 million worldwide and received praise from critics for Tarantino's direction and screenplay, the performances (particularly from DiCaprio and Pitt), cinematography, soundtrack, sound design, costume design, and production values. The National Board of Review and the American Film Institute named Once Upon a Time in Hollywood one of the top-ten films of 2019. Once Upon a Time in Hollywood was nominated for ten awards at the 92nd Academy Awards, winning two, and received numerous other accolades. A novelization, written by Tarantino in his debut as an author, was published on June 29, 2021. (Full article...)
Kato is a fictional character from The Green Hornet franchise. This character has appeared with the Green Hornet in radio, film, television, book and comic book versions. Kato is the Green Hornet's crime-fighting sidekick, and Britt Reid's manservant in civilian life, and has been played by a number of actors. On radio, Kato was initially played by Raymond Hayashi, then Roland Parker who had the role for most of the run, and in the later years Mickey Tolan and Paul Carnegie. Keye Luke took the role in the movie serials, and in the television series, he was portrayed by Bruce Lee. Jay Chou played Kato in the 2011 Green Hornet film. (Full article...)
Brandon Bruce Lee (February 1, 1965 – March 31, 1993) was an American actor. Establishing himself as a rising action star in the early 1990s, he landed his breakthrough role as Eric Draven in the supernatural superhero film The Crow (1994). However, Lee's career and life were cut short by his accidental death during the film's production.
Transitioning to Hollywood productions, Lee first starred in the Warner Brosbuddy cop film Showdown in Little Tokyo (1991), co-starring Dolph Lundgren. While it did not do well with audiences and critics upon its release, it later became a cult film. This was followed by a leading role in Rapid Fire (1992), produced by 20th Century Fox. Lee, alongside Jeff Imada, is also credited for the fight choreography, which contained elements of Jeet Kune Do. Though the film was not well-received, critics praised Lee's onscreen presence. (Full article...)
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In 2016, Magnetic Press published four issues of Bruce Lee: The Dragon Rises, co-written by Lee's daughter Shannon Lee and Jeff Kline, and illustrated by Brandon McKinney. The fictional story takes places in 2012 with Bruce Lee escaping from a science lab.
In 2018, Magnetic Press/Darby Pop Publishing released the one-shot Bruce Lee: The Walk Of The Dragon, also written by Shannon Lee. (Full article...)
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The Legend of Bruce Lee (Chinese: 李小龍傳奇) is a 2008 Chinese biographical television series based on the life story of martial artist and actor Bruce Lee. The 50-episode series was produced and broadcast by CCTV and began airing on October 12, 2008. It was intended to promote Chinese culture alongside the 2008 Beijing Summer Olympics.
It stars Hong Kong actor Danny Chan as Bruce Lee and American actress Michelle Lang as Lee's wife, Linda Lee Cadwell. The production period spanned nine months, with filming taking place in China, Hong Kong, Macau, the United States, Italy, and Thailand, and with a budget of 50 million yuan (US$7.3 million).
Dragon Lee (born August 12, 1958) is an actor and practitioner of taekwondo and hapkido. He made a name for himself as a martial arts film star in the 1970s and 80s. His birth name is Moon Kyung-seok, but he is also called Keo Ryong (literally "giant dragon") in South Korea. (Full article...)
Tao of Jeet Kune Do is a book expressing Bruce Lee's martial artsphilosophy and viewpoints, published posthumously (after Bruce Lee's death in 1973). The project for this book began in 1970 when Bruce Lee suffered a back injury during one of his practice sessions. During this time he could not train in martial arts. He was ordered by his doctors to wear a back brace for 6 months in order to recover from his injury. This was a very tiring and dispiriting time for Lee who was always very physically active.
It was during his convalescence that he decided to compile a treatise on the system or approach to martial arts that he was developing; he called it Jeet Kune Do. The bulk of these writings would become the "core set of writings". Many of these writings were done during a single session which provided natural continuity. Lee had also kept various notes throughout the development of his combat philosophy and these would become the disparate notes used in the book. Many of these notes were "sudden inspirations" which were incomplete and lacked any kind of a construct. The combination of the "core set of writings" and the "disparate notes" would be known as the text Tao of Jeet Kune Do.
In 1971, it was Lee's intent to finish the treatise that he started during his convalescence. However, his film career and work prevented him from doing so. He also vacillated about publishing his book as he felt that this work might be used for the wrong purposes. Lee's intent in writing the book was to record one man's way of thinking about the martial arts. It was to be a guidebook, not a set of instructions or "How to" manual to learn martial arts. (Full article...)
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Bruce Lee: The Lost Interview is the name given to the 9 December 1971 edition of The Pierre Berton Show, which featured martial artist/actor Bruce Lee in his only English speaking television interview. Its title is derived from its status; it was presumed lost for several years until its rediscovery and airing on 2 November 1994. Over the course of the interview, which was filmed in Hong Kong, Bruce Lee and Pierre Berton discuss Lee's career, various aspects of martial arts philosophy and the inherent problems faced by an Asian in pursuing stardom in Hollywood. A review of the interview by Bill Stockey said that Bruce Lee's "human side is exposed and he is portrayed as more approachable". (Full article...)
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Bruce Lee's Fighting Method is a book of volumes covering Bruce Lee's martial arts abilities of the Jeet Kune Do movement. The book is available as a single hardcover volume or a series of four paperback volumes. The text describes Bruce Lee's Kung Fufighting techniques, philosophy and training methods. This book was originally written in 1966 by Bruce Lee. However, Lee decided not to publish this work as he feared that instructors would use the fighting knowledge in this text to promote themselves. In 1978, after Bruce Lee's death, his widow Linda Lee Cadwell decided to make available the information on her husband's work. Lee's death changed the perspective of releasing the information that Bruce Lee himself had vacillated about. The book was published with the help of Mitoshi Uyehara. Uyehara was the founder and owner of Black Belt Magazine. During the early years of the publication, Uyehara served as the publisher. Bruce Lee contributed many articles to the publication during the 1960s and a friendship ensued between the two men. Uyehara, a martial artist in his own right, was a key personage in arranging Lee's material for publication. (Full article...)
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The straight blast is a martial arts technique popularized by Bruce Lee and associated with Wing Chun Kung Fu and Jeet Kune Do. It is one of Bruce Lee's most famous signature moves, and an international federation of gyms have been named after the technique.
The technique operates on the principle of using a sustained offense as a means of forcing an opponent to move on the defensive. The move consists of putting both fists perpendicularly above one another and moving them in a circular motion (starting forward and downward) in a tight formation with fists kept facing forward bent at the wrist outward and clenched vertically, compounded with running toward an opponent. This is intended to throw off the opponent while effectively dealing a barrage of centrifugally forced punches toward the center of the opponent's mass. A poorly executed or premature straight blast attack can usually be effectively countered by one or more kicks to the attacker's shin, knee, or groin.
In some of his books, Bruce Lee mentions how boxers would scoff at this 'funny' looking technique, but when they were not expecting it in sparring matches, they would take the brunt of the attack, be thrown off guard and defeated. (Full article...)
The Way of the Dragon was released in Hong Kong on 30 December 1972, and in the United States in August 1974. The film went on to gross an estimated US$130 million worldwide (equivalent to over $700 million adjusted for inflation), against a tight budget of $130,000, earning a thousand times its budget. It was the highest-grossing Hong Kong film up until Lee's next film Enter the Dragon (1973).
The film is primarily set in a restaurant in Rome. The owners are being harassed by a local crime boss, and request help from a relative in Hong Kong. The help arrives in the form of a young martial artist. The conflict between the restaurant staff and the gangsters soon escalates. (Full article...)
The version of the film that is commonly distributed in the West (USA) on public domain-type DVD and video labels runs 93 minutes in length. The British VHS-version released in 1979 runs 118 minutes. (Full article...)
Outline of underwater diving § Modes of underwater diving[edit]
{{ Transclude list item excerpts as random slideshow | Outline of underwater diving | section=Modes of underwater diving | paragraphs= | files=1 }}
Surface-supplied diver at the Monterey Bay Aquarium, Monterey, California Surface-supplied diving is a mode of underwater diving using equipment supplied with breathing gas through a diver's umbilical from the surface, either from the shore or from a diving support vessel, sometimes indirectly via a diving bell. This is different from scuba diving, where the diver's breathing equipment is completely self-contained and there is no essential link to the surface. The primary advantages of conventional surface supplied diving are lower risk of drowning and considerably larger breathing gas supply than scuba, allowing longer working periods and safer decompression. Disadvantages are the absolute limitation on diver mobility imposed by the length of the umbilical, encumbrance by the umbilical, and high logistical and equipment costs compared with scuba. The disadvantages restrict use of this mode of diving to applications where the diver operates within a small area, which is common in commercial diving work.
Airline, or hookah diving, and "compressor diving" are lower technology variants also using a breathing air supply from the surface. (Full article...)
Image 2
Surface-supplied diver at the Monterey Bay Aquarium, Monterey, California Surface-supplied diving is a mode of underwater diving using equipment supplied with breathing gas through a diver's umbilical from the surface, either from the shore or from a diving support vessel, sometimes indirectly via a diving bell. This is different from scuba diving, where the diver's breathing equipment is completely self-contained and there is no essential link to the surface. The primary advantages of conventional surface supplied diving are lower risk of drowning and considerably larger breathing gas supply than scuba, allowing longer working periods and safer decompression. Disadvantages are the absolute limitation on diver mobility imposed by the length of the umbilical, encumbrance by the umbilical, and high logistical and equipment costs compared with scuba. The disadvantages restrict use of this mode of diving to applications where the diver operates within a small area, which is common in commercial diving work.
Airline, or hookah diving, and "compressor diving" are lower technology variants also using a breathing air supply from the surface. (Full article...)
Image 3
A freediver on the ocean floor Freediving, free-diving, free diving, breath-hold diving, or skin diving, is a mode of underwater diving that relies on breath-holding until resurfacing rather than the use of breathing apparatus such as scuba gear.
Besides the limits of breath-hold, immersion in water and exposure to high ambient pressure also have physiological effects that limit the depths and duration possible in freediving.
Surface-supplied divers riding a stage to the underwater workplace
Underwater diving, as a human activity, is the practice of descending below the water's surface to interact with the environment. It is also often referred to as diving, an ambiguous term with several possible meanings, depending on context. Immersion in water and exposure to high ambient pressure have physiological effects that limit the depths and duration possible in ambient pressure diving. Humans are not physiologically and anatomically well-adapted to the environmental conditions of diving, and various equipment has been developed to extend the depth and duration of human dives, and allow different types of work to be done.
In ambient pressure diving, the diver is directly exposed to the pressure of the surrounding water. The ambient pressure diver may dive on breath-hold (freediving) or use breathing apparatus for scuba diving or surface-supplied diving, and the saturation diving technique reduces the risk of decompression sickness (DCS) after long-duration deep dives. Atmospheric diving suits (ADS) may be used to isolate the diver from high ambient pressure. Crewed submersibles can extend depth range to full ocean depth, and remotely controlled or robotic machines can reduce risk to humans.
The environment exposes the diver to a wide range of hazards, and though the risks are largely controlled by appropriate diving skills, training, types of equipment and breathing gases used depending on the mode, depth and purpose of diving, it remains a relatively dangerous activity. Professional diving is usually regulated by occupational health and safety legislation, while recreational diving may be entirely unregulated. Diving activities are restricted to maximum depths of about 40 metres (130 ft) for recreational scuba diving, 530 metres (1,740 ft) for commercial saturation diving, and 610 metres (2,000 ft) wearing atmospheric suits. Diving is also restricted to conditions which are not excessively hazardous, though the level of risk acceptable can vary, and fatal incidents may occur.
Recreational diving (sometimes called sport diving or subaquatics) is a popular leisure activity. Technical diving is a form of recreational diving under more challenging conditions. Professional diving (commercial diving, diving for research purposes, or for financial gain) involves working underwater. Public safety diving is the underwater work done by law enforcement, fire rescue, and underwater search and recovery dive teams. Military diving includes combat diving, clearance diving and ships husbandry. Deep sea diving is underwater diving, usually with surface-supplied equipment, and often refers to the use of standard diving dress with the traditional copper helmet. Hard hat diving is any form of diving with a helmet, including the standard copper helmet, and other forms of free-flow and lightweight demand helmets. The history of breath-hold diving goes back at least to classical times, and there is evidence of prehistoric hunting and gathering of seafoods that may have involved underwater swimming. Technical advances allowing the provision of breathing gas to a diver underwater at ambient pressure are recent, and self-contained breathing systems developed at an accelerated rate following the Second World War. (Full article...)
Image 5
Surface-supplied diver at the Monterey Bay Aquarium, Monterey, California Surface-supplied diving is a mode of underwater diving using equipment supplied with breathing gas through a diver's umbilical from the surface, either from the shore or from a diving support vessel, sometimes indirectly via a diving bell. This is different from scuba diving, where the diver's breathing equipment is completely self-contained and there is no essential link to the surface. The primary advantages of conventional surface supplied diving are lower risk of drowning and considerably larger breathing gas supply than scuba, allowing longer working periods and safer decompression. Disadvantages are the absolute limitation on diver mobility imposed by the length of the umbilical, encumbrance by the umbilical, and high logistical and equipment costs compared with scuba. The disadvantages restrict use of this mode of diving to applications where the diver operates within a small area, which is common in commercial diving work.
Airline, or hookah diving, and "compressor diving" are lower technology variants also using a breathing air supply from the surface. (Full article...)
Image 6
Recreational scuba diver Scuba diving is a mode of underwater diving whereby divers use breathing equipment that is completely independent of a surface breathing gas supply, and therefore has a limited but variable endurance. The name scuba is an anacronym for "Self-Contained Underwater Breathing Apparatus" and was coined by Christian J. Lambertsen in a patent submitted in 1952. Scuba divers carry their own source of breathing gas, usually compressed air, affording them greater independence and movement than surface-supplied divers, and more time underwater than free divers. Although the use of compressed air is common, a gas blend with a higher oxygen content, known as enriched air or nitrox, has become popular due to the reduced nitrogen intake during long or repetitive dives. Also, breathing gas diluted with helium may be used to reduce the effects of nitrogen narcosis during deeper dives.
Open-circuit scuba systems discharge the breathing gas into the environment as it is exhaled, and consist of one or more diving cylinders containing breathing gas at high pressure which is supplied to the diver at ambient pressure through a diving regulator. They may include additional cylinders for range extension, decompression gas or emergency breathing gas. Closed-circuit or semi-closed circuit rebreather scuba systems allow recycling of exhaled gases. The volume of gas used is reduced compared to that of open-circuit, so a smaller cylinder or cylinders may be used for an equivalent dive duration. Rebreathers extend the time spent underwater compared to open-circuit for the same metabolic gas consumption; they produce fewer bubbles and less noise than open-circuit scuba, which makes them attractive to covert military divers to avoid detection, scientific divers to avoid disturbing marine animals, and media divers to avoid bubble interference.
Scuba diving may be done recreationally or professionally in a number of applications, including scientific, military and public safety roles, but most commercial diving uses surface-supplied diving equipment when this is practicable. Scuba divers engaged in armed forces covert operations may be referred to as frogmen, combat divers or attack swimmers.
2nd Reconnaissance Battalion combat diver training with the Dräger LAR V rebreather
Rebreather diving is underwater diving using diving rebreathers, a class of underwater breathing apparatus which recirculate the breathing gas exhaled by the diver after replacing the oxygen used and removing the carbon dioxide metabolic product. Rebreather diving is practiced by recreational, military and scientific divers in applications where it has advantages over open circuit scuba, and surface supply of breathing gas is impracticable. The main advantages of rebreather diving are extended gas endurance, low noise levels, and lack of bubbles.
Rebreathers are generally used for scuba applications, but are also occasionally used for bailout systems for surface-supplied diving. Gas reclaim systems used for deep heliox diving use similar technology to rebreathers, as do saturation divinglife-support systems, but in these applications the gas recycling equipment is not carried by the diver. Atmospheric diving suits also carry rebreather technology to recycle breathing gas as part of the life-support system, but this article covers the procedures of ambient pressure diving using rebreathers carried by the diver.
Rebreathers are generally more complex to use than open circuit scuba, and have more potential points of failure, so acceptably safe use requires a greater level of skill, attention and situational awareness, which is usually derived from understanding the systems, diligent maintenance and overlearning the practical skills of operation and fault recovery. Fault tolerant design can make a rebreather less likely to fail in a way that immediately endangers the user, and reduces the task loading on the diver which in turn may lower the risk of operator error. (Full article...)
Image 8
Recreational scuba diver Scuba diving is a mode of underwater diving whereby divers use breathing equipment that is completely independent of a surface breathing gas supply, and therefore has a limited but variable endurance. The name scuba is an anacronym for "Self-Contained Underwater Breathing Apparatus" and was coined by Christian J. Lambertsen in a patent submitted in 1952. Scuba divers carry their own source of breathing gas, usually compressed air, affording them greater independence and movement than surface-supplied divers, and more time underwater than free divers. Although the use of compressed air is common, a gas blend with a higher oxygen content, known as enriched air or nitrox, has become popular due to the reduced nitrogen intake during long or repetitive dives. Also, breathing gas diluted with helium may be used to reduce the effects of nitrogen narcosis during deeper dives.
Open-circuit scuba systems discharge the breathing gas into the environment as it is exhaled, and consist of one or more diving cylinders containing breathing gas at high pressure which is supplied to the diver at ambient pressure through a diving regulator. They may include additional cylinders for range extension, decompression gas or emergency breathing gas. Closed-circuit or semi-closed circuit rebreather scuba systems allow recycling of exhaled gases. The volume of gas used is reduced compared to that of open-circuit, so a smaller cylinder or cylinders may be used for an equivalent dive duration. Rebreathers extend the time spent underwater compared to open-circuit for the same metabolic gas consumption; they produce fewer bubbles and less noise than open-circuit scuba, which makes them attractive to covert military divers to avoid detection, scientific divers to avoid disturbing marine animals, and media divers to avoid bubble interference.
Scuba diving may be done recreationally or professionally in a number of applications, including scientific, military and public safety roles, but most commercial diving uses surface-supplied diving equipment when this is practicable. Scuba divers engaged in armed forces covert operations may be referred to as frogmen, combat divers or attack swimmers.
Surface-supplied diver at the Monterey Bay Aquarium, Monterey, California Surface-supplied diving is a mode of underwater diving using equipment supplied with breathing gas through a diver's umbilical from the surface, either from the shore or from a diving support vessel, sometimes indirectly via a diving bell. This is different from scuba diving, where the diver's breathing equipment is completely self-contained and there is no essential link to the surface. The primary advantages of conventional surface supplied diving are lower risk of drowning and considerably larger breathing gas supply than scuba, allowing longer working periods and safer decompression. Disadvantages are the absolute limitation on diver mobility imposed by the length of the umbilical, encumbrance by the umbilical, and high logistical and equipment costs compared with scuba. The disadvantages restrict use of this mode of diving to applications where the diver operates within a small area, which is common in commercial diving work.
Airline, or hookah diving, and "compressor diving" are lower technology variants also using a breathing air supply from the surface. (Full article...)
Image 10
Atmospheric diving suit
An atmospheric diving suit (ADS), or single atmosphere diving suit is a small one-person articulated submersible which resembles a suit of armour, with elaborate pressure joints to allow articulation while maintaining an internal pressure of one atmosphere. An ADS can enable diving at depths of up to 2,300 feet (700 m) for many hours by eliminating the majority of significant physiological dangers associated with deep diving. The occupant of an ADS does not need to decompress, and there is no need for special breathing gas mixtures, so there is little danger of decompression sickness or nitrogen narcosis when the ADS is functioning properly. An ADS can permit less skilled swimmers to complete deep dives, albeit at the expense of dexterity.
Atmospheric diving suits in current use include the Newtsuit, Exosuit, Hardsuit and the WASP, all of which are self-contained hard suits that incorporate propulsion units. The Hardsuit is constructed from cast aluminum (forged aluminum in a version constructed for the US Navy for submarine rescue); the upper hull is made from cast aluminum, while the bottom dome is machined aluminum. The WASP is of glass-reinforced plastic (GRP) body tube construction. (Full article...)
Image 11
Saturation diver working on the USS Monitor wreck at 70 m (230 ft) depth. Saturation diving is diving for periods long enough to bring all tissues into equilibrium with the partial pressures of the inert components of the breathing gas used. It is a diving mode that reduces the number of decompressions divers working at great depths must undergo by only decompressing divers once at the end of the diving operation, which may last days to weeks, having them remain under pressure for the whole period. A diver breathing pressurized gas accumulates dissolved inert gas used in the breathing mixture to dilute the oxygen to a non-toxic level in the tissues, which can cause potentially fatal decompression sickness ("the bends") if permitted to come out of solution within the body tissues; hence, returning to the surface safely requires lengthy decompression so that the inert gases can be eliminated via the lungs. Once the dissolved gases in a diver's tissues reach the saturation point, however, decompression time does not increase with further exposure, as no more inert gas is accumulated.
Saturation diving takes advantage of this by having divers remain in that saturated state. When not in the water, the divers live in a sealed environment which maintains their pressurised state; this can be an ambient pressure underwater habitat or a saturation system at the surface, with transfer to and from the pressurised living quarters to the equivalent depth underwater via a closed, pressurised diving bell. This may be maintained for up to several weeks, and divers are decompressed to surface pressure only once, at the end of their tour of duty. By limiting the number of decompressions in this way, and using a conservative decompression schedule the risk of decompression sickness is significantly reduced, and the total time spent decompressing is minimised. Saturation divers typically breathe a helium–oxygen mixture to prevent nitrogen narcosis, and limit work of breathing, but at shallow depths saturation diving has been done on nitrox mixtures.
Most of the physiological and medical aspects of diving to the same depths are much the same in saturation and bell-bounce ambient pressure diving, or are less of a problem, but there are medical and psychological effects of living under saturation for extended periods.
Saturation diving is a specialized form of diving; of the 3,300 commercial divers employed in the United States in 2015, 336 were saturation divers. Special training and certification is required, as the activity is inherently hazardous, and a set of standard operating procedures, emergency procedures, and a range of specialised equipment is used to control the risk, that require consistently correct performance by all the members of an extended diving team. The combination of relatively large skilled personnel requirements, complex engineering, and bulky, heavy equipment required to support a saturation diving project make it an expensive diving mode, but it allows direct human intervention at places that would not otherwise be practical, and where it is applied, it is generally more economically viable than other options, if such exist. (Full article...)
Image 12
Surface-supplied diver at the Monterey Bay Aquarium, Monterey, California Surface-supplied diving is a mode of underwater diving using equipment supplied with breathing gas through a diver's umbilical from the surface, either from the shore or from a diving support vessel, sometimes indirectly via a diving bell. This is different from scuba diving, where the diver's breathing equipment is completely self-contained and there is no essential link to the surface. The primary advantages of conventional surface supplied diving are lower risk of drowning and considerably larger breathing gas supply than scuba, allowing longer working periods and safer decompression. Disadvantages are the absolute limitation on diver mobility imposed by the length of the umbilical, encumbrance by the umbilical, and high logistical and equipment costs compared with scuba. The disadvantages restrict use of this mode of diving to applications where the diver operates within a small area, which is common in commercial diving work.
Airline, or hookah diving, and "compressor diving" are lower technology variants also using a breathing air supply from the surface. (Full article...)
Image 13
Surface-supplied diver at the Monterey Bay Aquarium, Monterey, California Surface-supplied diving is a mode of underwater diving using equipment supplied with breathing gas through a diver's umbilical from the surface, either from the shore or from a diving support vessel, sometimes indirectly via a diving bell. This is different from scuba diving, where the diver's breathing equipment is completely self-contained and there is no essential link to the surface. The primary advantages of conventional surface supplied diving are lower risk of drowning and considerably larger breathing gas supply than scuba, allowing longer working periods and safer decompression. Disadvantages are the absolute limitation on diver mobility imposed by the length of the umbilical, encumbrance by the umbilical, and high logistical and equipment costs compared with scuba. The disadvantages restrict use of this mode of diving to applications where the diver operates within a small area, which is common in commercial diving work.
Airline, or hookah diving, and "compressor diving" are lower technology variants also using a breathing air supply from the surface. (Full article...)
Image 14
Surface-supplied divers riding a stage to the underwater workplace
Underwater diving, as a human activity, is the practice of descending below the water's surface to interact with the environment. It is also often referred to as diving, an ambiguous term with several possible meanings, depending on context. Immersion in water and exposure to high ambient pressure have physiological effects that limit the depths and duration possible in ambient pressure diving. Humans are not physiologically and anatomically well-adapted to the environmental conditions of diving, and various equipment has been developed to extend the depth and duration of human dives, and allow different types of work to be done.
In ambient pressure diving, the diver is directly exposed to the pressure of the surrounding water. The ambient pressure diver may dive on breath-hold (freediving) or use breathing apparatus for scuba diving or surface-supplied diving, and the saturation diving technique reduces the risk of decompression sickness (DCS) after long-duration deep dives. Atmospheric diving suits (ADS) may be used to isolate the diver from high ambient pressure. Crewed submersibles can extend depth range to full ocean depth, and remotely controlled or robotic machines can reduce risk to humans.
The environment exposes the diver to a wide range of hazards, and though the risks are largely controlled by appropriate diving skills, training, types of equipment and breathing gases used depending on the mode, depth and purpose of diving, it remains a relatively dangerous activity. Professional diving is usually regulated by occupational health and safety legislation, while recreational diving may be entirely unregulated. Diving activities are restricted to maximum depths of about 40 metres (130 ft) for recreational scuba diving, 530 metres (1,740 ft) for commercial saturation diving, and 610 metres (2,000 ft) wearing atmospheric suits. Diving is also restricted to conditions which are not excessively hazardous, though the level of risk acceptable can vary, and fatal incidents may occur.
Recreational diving (sometimes called sport diving or subaquatics) is a popular leisure activity. Technical diving is a form of recreational diving under more challenging conditions. Professional diving (commercial diving, diving for research purposes, or for financial gain) involves working underwater. Public safety diving is the underwater work done by law enforcement, fire rescue, and underwater search and recovery dive teams. Military diving includes combat diving, clearance diving and ships husbandry. Deep sea diving is underwater diving, usually with surface-supplied equipment, and often refers to the use of standard diving dress with the traditional copper helmet. Hard hat diving is any form of diving with a helmet, including the standard copper helmet, and other forms of free-flow and lightweight demand helmets. The history of breath-hold diving goes back at least to classical times, and there is evidence of prehistoric hunting and gathering of seafoods that may have involved underwater swimming. Technical advances allowing the provision of breathing gas to a diver underwater at ambient pressure are recent, and self-contained breathing systems developed at an accelerated rate following the Second World War. (Full article...)
A freediver on the ocean floor Freediving, free-diving, free diving, breath-hold diving, or skin diving, is a mode of underwater diving that relies on breath-holding until resurfacing rather than the use of breathing apparatus such as scuba gear.
Besides the limits of breath-hold, immersion in water and exposure to high ambient pressure also have physiological effects that limit the depths and duration possible in freediving.
An atmospheric diving suit (ADS), or single atmosphere diving suit is a small one-person articulated submersible which resembles a suit of armour, with elaborate pressure joints to allow articulation while maintaining an internal pressure of one atmosphere. An ADS can enable diving at depths of up to 2,300 feet (700 m) for many hours by eliminating the majority of significant physiological dangers associated with deep diving. The occupant of an ADS does not need to decompress, and there is no need for special breathing gas mixtures, so there is little danger of decompression sickness or nitrogen narcosis when the ADS is functioning properly. An ADS can permit less skilled swimmers to complete deep dives, albeit at the expense of dexterity.
Atmospheric diving suits in current use include the Newtsuit, Exosuit, Hardsuit and the WASP, all of which are self-contained hard suits that incorporate propulsion units. The Hardsuit is constructed from cast aluminum (forged aluminum in a version constructed for the US Navy for submarine rescue); the upper hull is made from cast aluminum, while the bottom dome is machined aluminum. The WASP is of glass-reinforced plastic (GRP) body tube construction. (Full article...)
Image 3
Recreational scuba diver Scuba diving is a mode of underwater diving whereby divers use breathing equipment that is completely independent of a surface breathing gas supply, and therefore has a limited but variable endurance. The name scuba is an anacronym for "Self-Contained Underwater Breathing Apparatus" and was coined by Christian J. Lambertsen in a patent submitted in 1952. Scuba divers carry their own source of breathing gas, usually compressed air, affording them greater independence and movement than surface-supplied divers, and more time underwater than free divers. Although the use of compressed air is common, a gas blend with a higher oxygen content, known as enriched air or nitrox, has become popular due to the reduced nitrogen intake during long or repetitive dives. Also, breathing gas diluted with helium may be used to reduce the effects of nitrogen narcosis during deeper dives.
Open-circuit scuba systems discharge the breathing gas into the environment as it is exhaled, and consist of one or more diving cylinders containing breathing gas at high pressure which is supplied to the diver at ambient pressure through a diving regulator. They may include additional cylinders for range extension, decompression gas or emergency breathing gas. Closed-circuit or semi-closed circuit rebreather scuba systems allow recycling of exhaled gases. The volume of gas used is reduced compared to that of open-circuit, so a smaller cylinder or cylinders may be used for an equivalent dive duration. Rebreathers extend the time spent underwater compared to open-circuit for the same metabolic gas consumption; they produce fewer bubbles and less noise than open-circuit scuba, which makes them attractive to covert military divers to avoid detection, scientific divers to avoid disturbing marine animals, and media divers to avoid bubble interference.
Scuba diving may be done recreationally or professionally in a number of applications, including scientific, military and public safety roles, but most commercial diving uses surface-supplied diving equipment when this is practicable. Scuba divers engaged in armed forces covert operations may be referred to as frogmen, combat divers or attack swimmers.
Surface-supplied diver at the Monterey Bay Aquarium, Monterey, California Surface-supplied diving is a mode of underwater diving using equipment supplied with breathing gas through a diver's umbilical from the surface, either from the shore or from a diving support vessel, sometimes indirectly via a diving bell. This is different from scuba diving, where the diver's breathing equipment is completely self-contained and there is no essential link to the surface. The primary advantages of conventional surface supplied diving are lower risk of drowning and considerably larger breathing gas supply than scuba, allowing longer working periods and safer decompression. Disadvantages are the absolute limitation on diver mobility imposed by the length of the umbilical, encumbrance by the umbilical, and high logistical and equipment costs compared with scuba. The disadvantages restrict use of this mode of diving to applications where the diver operates within a small area, which is common in commercial diving work.
Airline, or hookah diving, and "compressor diving" are lower technology variants also using a breathing air supply from the surface. (Full article...)
Image 5
Surface-supplied diver at the Monterey Bay Aquarium, Monterey, California Surface-supplied diving is a mode of underwater diving using equipment supplied with breathing gas through a diver's umbilical from the surface, either from the shore or from a diving support vessel, sometimes indirectly via a diving bell. This is different from scuba diving, where the diver's breathing equipment is completely self-contained and there is no essential link to the surface. The primary advantages of conventional surface supplied diving are lower risk of drowning and considerably larger breathing gas supply than scuba, allowing longer working periods and safer decompression. Disadvantages are the absolute limitation on diver mobility imposed by the length of the umbilical, encumbrance by the umbilical, and high logistical and equipment costs compared with scuba. The disadvantages restrict use of this mode of diving to applications where the diver operates within a small area, which is common in commercial diving work.
Airline, or hookah diving, and "compressor diving" are lower technology variants also using a breathing air supply from the surface. (Full article...)
Image 6
2nd Reconnaissance Battalion combat diver training with the Dräger LAR V rebreather
Rebreather diving is underwater diving using diving rebreathers, a class of underwater breathing apparatus which recirculate the breathing gas exhaled by the diver after replacing the oxygen used and removing the carbon dioxide metabolic product. Rebreather diving is practiced by recreational, military and scientific divers in applications where it has advantages over open circuit scuba, and surface supply of breathing gas is impracticable. The main advantages of rebreather diving are extended gas endurance, low noise levels, and lack of bubbles.
Rebreathers are generally used for scuba applications, but are also occasionally used for bailout systems for surface-supplied diving. Gas reclaim systems used for deep heliox diving use similar technology to rebreathers, as do saturation divinglife-support systems, but in these applications the gas recycling equipment is not carried by the diver. Atmospheric diving suits also carry rebreather technology to recycle breathing gas as part of the life-support system, but this article covers the procedures of ambient pressure diving using rebreathers carried by the diver.
Rebreathers are generally more complex to use than open circuit scuba, and have more potential points of failure, so acceptably safe use requires a greater level of skill, attention and situational awareness, which is usually derived from understanding the systems, diligent maintenance and overlearning the practical skills of operation and fault recovery. Fault tolerant design can make a rebreather less likely to fail in a way that immediately endangers the user, and reduces the task loading on the diver which in turn may lower the risk of operator error. (Full article...)
Image 7
Surface-supplied divers riding a stage to the underwater workplace
Underwater diving, as a human activity, is the practice of descending below the water's surface to interact with the environment. It is also often referred to as diving, an ambiguous term with several possible meanings, depending on context. Immersion in water and exposure to high ambient pressure have physiological effects that limit the depths and duration possible in ambient pressure diving. Humans are not physiologically and anatomically well-adapted to the environmental conditions of diving, and various equipment has been developed to extend the depth and duration of human dives, and allow different types of work to be done.
In ambient pressure diving, the diver is directly exposed to the pressure of the surrounding water. The ambient pressure diver may dive on breath-hold (freediving) or use breathing apparatus for scuba diving or surface-supplied diving, and the saturation diving technique reduces the risk of decompression sickness (DCS) after long-duration deep dives. Atmospheric diving suits (ADS) may be used to isolate the diver from high ambient pressure. Crewed submersibles can extend depth range to full ocean depth, and remotely controlled or robotic machines can reduce risk to humans.
The environment exposes the diver to a wide range of hazards, and though the risks are largely controlled by appropriate diving skills, training, types of equipment and breathing gases used depending on the mode, depth and purpose of diving, it remains a relatively dangerous activity. Professional diving is usually regulated by occupational health and safety legislation, while recreational diving may be entirely unregulated. Diving activities are restricted to maximum depths of about 40 metres (130 ft) for recreational scuba diving, 530 metres (1,740 ft) for commercial saturation diving, and 610 metres (2,000 ft) wearing atmospheric suits. Diving is also restricted to conditions which are not excessively hazardous, though the level of risk acceptable can vary, and fatal incidents may occur.
Recreational diving (sometimes called sport diving or subaquatics) is a popular leisure activity. Technical diving is a form of recreational diving under more challenging conditions. Professional diving (commercial diving, diving for research purposes, or for financial gain) involves working underwater. Public safety diving is the underwater work done by law enforcement, fire rescue, and underwater search and recovery dive teams. Military diving includes combat diving, clearance diving and ships husbandry. Deep sea diving is underwater diving, usually with surface-supplied equipment, and often refers to the use of standard diving dress with the traditional copper helmet. Hard hat diving is any form of diving with a helmet, including the standard copper helmet, and other forms of free-flow and lightweight demand helmets. The history of breath-hold diving goes back at least to classical times, and there is evidence of prehistoric hunting and gathering of seafoods that may have involved underwater swimming. Technical advances allowing the provision of breathing gas to a diver underwater at ambient pressure are recent, and self-contained breathing systems developed at an accelerated rate following the Second World War. (Full article...)
Image 8
Surface-supplied diver at the Monterey Bay Aquarium, Monterey, California Surface-supplied diving is a mode of underwater diving using equipment supplied with breathing gas through a diver's umbilical from the surface, either from the shore or from a diving support vessel, sometimes indirectly via a diving bell. This is different from scuba diving, where the diver's breathing equipment is completely self-contained and there is no essential link to the surface. The primary advantages of conventional surface supplied diving are lower risk of drowning and considerably larger breathing gas supply than scuba, allowing longer working periods and safer decompression. Disadvantages are the absolute limitation on diver mobility imposed by the length of the umbilical, encumbrance by the umbilical, and high logistical and equipment costs compared with scuba. The disadvantages restrict use of this mode of diving to applications where the diver operates within a small area, which is common in commercial diving work.
Airline, or hookah diving, and "compressor diving" are lower technology variants also using a breathing air supply from the surface. (Full article...)
Image 9
Surface-supplied diver at the Monterey Bay Aquarium, Monterey, California Surface-supplied diving is a mode of underwater diving using equipment supplied with breathing gas through a diver's umbilical from the surface, either from the shore or from a diving support vessel, sometimes indirectly via a diving bell. This is different from scuba diving, where the diver's breathing equipment is completely self-contained and there is no essential link to the surface. The primary advantages of conventional surface supplied diving are lower risk of drowning and considerably larger breathing gas supply than scuba, allowing longer working periods and safer decompression. Disadvantages are the absolute limitation on diver mobility imposed by the length of the umbilical, encumbrance by the umbilical, and high logistical and equipment costs compared with scuba. The disadvantages restrict use of this mode of diving to applications where the diver operates within a small area, which is common in commercial diving work.
Airline, or hookah diving, and "compressor diving" are lower technology variants also using a breathing air supply from the surface. (Full article...)
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Saturation diver working on the USS Monitor wreck at 70 m (230 ft) depth. Saturation diving is diving for periods long enough to bring all tissues into equilibrium with the partial pressures of the inert components of the breathing gas used. It is a diving mode that reduces the number of decompressions divers working at great depths must undergo by only decompressing divers once at the end of the diving operation, which may last days to weeks, having them remain under pressure for the whole period. A diver breathing pressurized gas accumulates dissolved inert gas used in the breathing mixture to dilute the oxygen to a non-toxic level in the tissues, which can cause potentially fatal decompression sickness ("the bends") if permitted to come out of solution within the body tissues; hence, returning to the surface safely requires lengthy decompression so that the inert gases can be eliminated via the lungs. Once the dissolved gases in a diver's tissues reach the saturation point, however, decompression time does not increase with further exposure, as no more inert gas is accumulated.
Saturation diving takes advantage of this by having divers remain in that saturated state. When not in the water, the divers live in a sealed environment which maintains their pressurised state; this can be an ambient pressure underwater habitat or a saturation system at the surface, with transfer to and from the pressurised living quarters to the equivalent depth underwater via a closed, pressurised diving bell. This may be maintained for up to several weeks, and divers are decompressed to surface pressure only once, at the end of their tour of duty. By limiting the number of decompressions in this way, and using a conservative decompression schedule the risk of decompression sickness is significantly reduced, and the total time spent decompressing is minimised. Saturation divers typically breathe a helium–oxygen mixture to prevent nitrogen narcosis, and limit work of breathing, but at shallow depths saturation diving has been done on nitrox mixtures.
Most of the physiological and medical aspects of diving to the same depths are much the same in saturation and bell-bounce ambient pressure diving, or are less of a problem, but there are medical and psychological effects of living under saturation for extended periods.
Saturation diving is a specialized form of diving; of the 3,300 commercial divers employed in the United States in 2015, 336 were saturation divers. Special training and certification is required, as the activity is inherently hazardous, and a set of standard operating procedures, emergency procedures, and a range of specialised equipment is used to control the risk, that require consistently correct performance by all the members of an extended diving team. The combination of relatively large skilled personnel requirements, complex engineering, and bulky, heavy equipment required to support a saturation diving project make it an expensive diving mode, but it allows direct human intervention at places that would not otherwise be practical, and where it is applied, it is generally more economically viable than other options, if such exist. (Full article...)
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Surface-supplied diver at the Monterey Bay Aquarium, Monterey, California Surface-supplied diving is a mode of underwater diving using equipment supplied with breathing gas through a diver's umbilical from the surface, either from the shore or from a diving support vessel, sometimes indirectly via a diving bell. This is different from scuba diving, where the diver's breathing equipment is completely self-contained and there is no essential link to the surface. The primary advantages of conventional surface supplied diving are lower risk of drowning and considerably larger breathing gas supply than scuba, allowing longer working periods and safer decompression. Disadvantages are the absolute limitation on diver mobility imposed by the length of the umbilical, encumbrance by the umbilical, and high logistical and equipment costs compared with scuba. The disadvantages restrict use of this mode of diving to applications where the diver operates within a small area, which is common in commercial diving work.
Airline, or hookah diving, and "compressor diving" are lower technology variants also using a breathing air supply from the surface. (Full article...)
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Recreational scuba diver Scuba diving is a mode of underwater diving whereby divers use breathing equipment that is completely independent of a surface breathing gas supply, and therefore has a limited but variable endurance. The name scuba is an anacronym for "Self-Contained Underwater Breathing Apparatus" and was coined by Christian J. Lambertsen in a patent submitted in 1952. Scuba divers carry their own source of breathing gas, usually compressed air, affording them greater independence and movement than surface-supplied divers, and more time underwater than free divers. Although the use of compressed air is common, a gas blend with a higher oxygen content, known as enriched air or nitrox, has become popular due to the reduced nitrogen intake during long or repetitive dives. Also, breathing gas diluted with helium may be used to reduce the effects of nitrogen narcosis during deeper dives.
Open-circuit scuba systems discharge the breathing gas into the environment as it is exhaled, and consist of one or more diving cylinders containing breathing gas at high pressure which is supplied to the diver at ambient pressure through a diving regulator. They may include additional cylinders for range extension, decompression gas or emergency breathing gas. Closed-circuit or semi-closed circuit rebreather scuba systems allow recycling of exhaled gases. The volume of gas used is reduced compared to that of open-circuit, so a smaller cylinder or cylinders may be used for an equivalent dive duration. Rebreathers extend the time spent underwater compared to open-circuit for the same metabolic gas consumption; they produce fewer bubbles and less noise than open-circuit scuba, which makes them attractive to covert military divers to avoid detection, scientific divers to avoid disturbing marine animals, and media divers to avoid bubble interference.
Scuba diving may be done recreationally or professionally in a number of applications, including scientific, military and public safety roles, but most commercial diving uses surface-supplied diving equipment when this is practicable. Scuba divers engaged in armed forces covert operations may be referred to as frogmen, combat divers or attack swimmers.
Surface-supplied divers riding a stage to the underwater workplace
Underwater diving, as a human activity, is the practice of descending below the water's surface to interact with the environment. It is also often referred to as diving, an ambiguous term with several possible meanings, depending on context. Immersion in water and exposure to high ambient pressure have physiological effects that limit the depths and duration possible in ambient pressure diving. Humans are not physiologically and anatomically well-adapted to the environmental conditions of diving, and various equipment has been developed to extend the depth and duration of human dives, and allow different types of work to be done.
In ambient pressure diving, the diver is directly exposed to the pressure of the surrounding water. The ambient pressure diver may dive on breath-hold (freediving) or use breathing apparatus for scuba diving or surface-supplied diving, and the saturation diving technique reduces the risk of decompression sickness (DCS) after long-duration deep dives. Atmospheric diving suits (ADS) may be used to isolate the diver from high ambient pressure. Crewed submersibles can extend depth range to full ocean depth, and remotely controlled or robotic machines can reduce risk to humans.
The environment exposes the diver to a wide range of hazards, and though the risks are largely controlled by appropriate diving skills, training, types of equipment and breathing gases used depending on the mode, depth and purpose of diving, it remains a relatively dangerous activity. Professional diving is usually regulated by occupational health and safety legislation, while recreational diving may be entirely unregulated. Diving activities are restricted to maximum depths of about 40 metres (130 ft) for recreational scuba diving, 530 metres (1,740 ft) for commercial saturation diving, and 610 metres (2,000 ft) wearing atmospheric suits. Diving is also restricted to conditions which are not excessively hazardous, though the level of risk acceptable can vary, and fatal incidents may occur.
Recreational diving (sometimes called sport diving or subaquatics) is a popular leisure activity. Technical diving is a form of recreational diving under more challenging conditions. Professional diving (commercial diving, diving for research purposes, or for financial gain) involves working underwater. Public safety diving is the underwater work done by law enforcement, fire rescue, and underwater search and recovery dive teams. Military diving includes combat diving, clearance diving and ships husbandry. Deep sea diving is underwater diving, usually with surface-supplied equipment, and often refers to the use of standard diving dress with the traditional copper helmet. Hard hat diving is any form of diving with a helmet, including the standard copper helmet, and other forms of free-flow and lightweight demand helmets. The history of breath-hold diving goes back at least to classical times, and there is evidence of prehistoric hunting and gathering of seafoods that may have involved underwater swimming. Technical advances allowing the provision of breathing gas to a diver underwater at ambient pressure are recent, and self-contained breathing systems developed at an accelerated rate following the Second World War. (Full article...)
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Surface-supplied diver at the Monterey Bay Aquarium, Monterey, California Surface-supplied diving is a mode of underwater diving using equipment supplied with breathing gas through a diver's umbilical from the surface, either from the shore or from a diving support vessel, sometimes indirectly via a diving bell. This is different from scuba diving, where the diver's breathing equipment is completely self-contained and there is no essential link to the surface. The primary advantages of conventional surface supplied diving are lower risk of drowning and considerably larger breathing gas supply than scuba, allowing longer working periods and safer decompression. Disadvantages are the absolute limitation on diver mobility imposed by the length of the umbilical, encumbrance by the umbilical, and high logistical and equipment costs compared with scuba. The disadvantages restrict use of this mode of diving to applications where the diver operates within a small area, which is common in commercial diving work.