Along with several USGS colleagues, Cameron Wobus (CIRES), Bob Anderson, Irina Overeem, Nora Matell (all INSTAAR), and Gary Clow (INSTAAR/USGS) created a video of erosion along Alaska’s arctic coast that was posted by Andrew Revkin on his New York Times Dot Earth Blog. The video is based on time-lapse photography of a point east of Barrow, the northernmost community in the United States. The video for July 2008 shows that the 5 m-high, ice-rich bluffs are thawing quickly in the heat of the summer and toppling into the ocean, where they melt away within days. This observation is consistent with other studies showing regional rates of erosion in excess of 6 meters per year – and local rates as much as 100 m in a single season. Longer-term studies show that the rate of erosion is faster and more uniform than historical rates. This acceleration of coastal erosion is just one of many environmental impacts observed with continued warming of the Arctic. The team is currently studying the relative influence of direct thermal degradation of the ground-ice rich coastline versus increased wave attack associated with longer ice-free conditions in the adjacent Beaufort Sea.
Coastal retreat is a particular problem in Alaska, where coastal communities, numerous sites housing potential contaminants, and millions of dollars in petroleum infrastructure are all at risk of being undermined by coastline retreat. In addition, coastal erosion has the potential to create substantial changes in surface hydrology along the Arctic coastal plain by breaching large thaw lakes and threatening the habitat for migratory birds and other wildlife in this sensitive ecosystem.