File talk:U. S. Sea Level Trends 1900-2003.gif

This image (set of charts) invites discussion and clarification.

Specifically, is the sea level rising at different rates relative to some mean sea level, or is the reported sea level change relative to a regional continental level? Why would sea level be increasing faster near Galveston but actually be decreasing near Sitka? This suggests that the sea level is being measured relative to the regional continental level and thus reflects subsidence (for Galveston) and uplift (for Sitka.) A reference to the source of this graph would be very helpful. Pondhockey (talk) 06:09, 30 January 2015 (UTC)