Rapid Wastage of Alaska's Glaciers
Glaciers in Alaska and neighboring Canada cover about 90,000 square kilometers or about 13 percent of the mountain glacier area on Earth; they include some of the largest ice masses outside of Greenland and Antarctica. A group from the University of Alaska's Geophysical Institute measured sixty-seven glaciers in the region, which represents about 20 percent of the total glacierized area, and compared them to maps from the 1950s1. From the mid-1950s to the mid-1990s these glaciers lost on average about 0.5 meters of thickness per year. From the mid-1990s to 2001 the rate of thinning increased to 1.8 meters per year. These recent losses are nearly double the estimated annual loss from the entire Greenland Ice Sheet and form the largest glacial contribution to rising sea level yet measured.
We spoke with Keith Echelmeyer about this innovative work and its implications for sea level changes.