ARCUS 14th Annual Meeting and Arctic Forum 2002

Rapid Wastage of Alaska Glaciers and their Contribution to Rising Sea Level (Previously entitled: Elevation and volume changes of Alaskan glaciers, measured from airborne laser altimetry)

Anthony Arendt¹, K. Echelmeyer², W. Harrison³, C. Lingle⁴, V. Valentine^5
1Department of Geophysics, University of Alaska Fairbanks, PO Box 757320, Fairbanks, AK, 99775-7320, USA, Phone 907-474-7146, Fax 907-474-7290
²Department of Geology and Geophysics, University of Alaska Fairbanks, PO Box 755780, Fairbanks, AK, 99775-5780, USA, Phone 907/474-7477, Fax 907/474-7290, kechel@gi.alaska.edu
³Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, 99775-7320, USA
⁴Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, 99775-7320, USA
⁵University of Alaska Fairbanks, PO Box 757320, Fairbanks, AK, 99775-7320, USA, Phone 907-474-7146, Fax 907-474-7290

We have used airborne laser altimetry to estimate volume changes of 67 glaciers in Alaska from the mid-1950s to the mid-1990s. The average rate of thickness change of these glaciers was -0.45 m/year. Extrapolation to all glaciers in Alaska yields an estimated total annual volume change of -52±7 km³/year (water equivalent), equivalent to a rise in sea level (SLE) of 0.14±0.02 mm/year. Repeat measurements of 27 glaciers from the mid-1990s to 2000-01 suggest an increased average rate of thinning, -1.1 m/year. This leads to an extrapolated annual volume loss from Alaska glaciers equal to -91±28 km³/year, or 0.25±0.08 mm/year SLE, during the last decade. These recent losses are about 78% larger than the estimated annual loss from the entire Greenland Ice Sheet during the same time period, and are much higher than previously published loss-estimates for Alaska glaciers. They form the largest glaciological contri-bution to rising sea level yet measured.

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