Islands of Portland

Welcome to Greenhouse Earth–Portland edition. The Portland archipelago awaits your descendants.

This map has been updated!

Here’s the old Portland map

Update: Someone pointed out these maps showing the Missoula floods–Very cool!  http://www.oregonlive.com/environment/index.ssf/2012/06/lidar_map_shows_path_of_missou.html

http://www.oregongeology.org/pubs/ims/p-ims-036.htm

Check out  the original San Francisco map–Burrito Justice & Brian Stokle’s map of San Francisco.

This is the second in a series of sea-level-rise maps. Seattle was the first. There are more cities in various stages of completion, and I’ll be posting them as they are finished. Right now, I’m working on all the major North American West Coast cities, except for San Francisco, which has already been done. The loose confederation of future city-states is slowly taking form.

What fascinates me the most about this project is the landforms, bays, seas and other geographies that emerge. In Seattle’s case, the landforms were compelling up close–the hills and valleys of Seattle’s glacial topography made amazing islands and passages. For Portland, it gets interesting as you zoom out–the inland seas, islands, and fjords are what make this map fascinating to me. The Cordilleran Ice Sheet had massive influences on the geologies of both cities, but only indirectly here. The sheet didn’t extend this far south, but the Missoula Floods swept through many times–the result of breaking ice dams from the glaciers upstream.

Let me stress the approximate nature of the sea rise level of these visualizations. For the Seattle map, I used 240 feet. For this map, I’m using 250. The USGS has estimated that the total sea rise possible from ice sheet melt is 80.32 meters. Because I’m trying to convey both terror and entertainment, I put the sea level wherever the bays and islands look the most interesting, up to the maximum of about 263 feet.

Sea level rise of this extreme has been estimated to take anywhere from 1,000 to 10,000 years, which may seem like a long time in the context of a single human life span, but in terms of human civilizations, it’s really not. Anyway, this end point is not really important. The real damage will come long before then–a small fraction of this 250′ level will devastate coastal cities.

Preview details of map: