Mean annual coastal
erosion on Alaska’s
meters Beaufort Sea
Mean annual
coastal erosion on
meters East Siberian Sea
Warming Arctic
sufficient data for confirmation, says On average, Ping says, 70 percent of
Volker Rachold of the International Arctic coastline is ice — sometimes tiny
comes unglued Arctic Science Committee in Potsdam, crystals, other times blocks meters on a
Germany, which copublished the new side. Ping’s team reports online April 20
Rising rates of erosion strike report with the Land- Ocean Interactions in the Journal of Geophysical Research
in the Coastal Zone Project, the Arctic that height above sea level and ice content
region’s ice-rich coastlines
Council’s Arctic Monitoring and Assess- are key predictors of erosion risk.
ment Programme, and the International The most ice-rich soils face “double
By Janet Raloff
Permafrost Association. jeopardy” from warming, Ping explains.
Arctic coastlines — a third of the globe’s Arctic coasts are especially vulnerable, Icier soils initially expand to create
shores —are retreating an average of half says Rachold, because here “ice is what high bluffs, vulnerable to undercutting
a meter annually, a 10-nation regional holdseverythingtogether.” Socoastalsed- by warming waters and waves as seas
assessment concludes. A warming cli- iments are coming unglued in the region, are increasingly freed of year-round ice
mate is the apparent cause, according to a where global warming is exaggerated. cover. As warming air tha ws icy patches
related Alaskan study that also calculates A related analysis, focusing on Alas- in the region’s permafrost, affected soils
the amount of carbon and other nutrients ka’s Beaufort Sea coast, finds that land can sink to sea level or below.
in soil being washed into Arctic waters. losses now are twice the rate typical of By narrowing its focus to a meters-
Annual erosion in some spots exceeds the 1950s through 1980. Chien-Lu Ping long scale in breadth and depth, Ping’s
8 meters, the new State of the Arctic of the Palmer Research Center at the groupfoundastrongandconvincinglink
Coast Report estimates. That rate is University of Alaska Fairbanks and col- between ice content and Arctic coastal
higher thananywhere else on Earth—and leagues quantified the rates and then, erosion, says geoscientist Paul Overduin
escalating. Scientists had suspected as for the first time, correlated erosion risk of the Alfred Wegener Institute for Polar
much, but until now had not amassed with soil type. and Marine Research in Potsdam.
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