|Find Glacier Flow Speed Data|
Alaska Glacier Flow Speed, 2007-2011
The first near-comprehensive dataset of wintertime glacier-flow speeds throughout Alaska — available here and described in Burgess et al., Nature Communications, 2013 — reveals complex patterns of glacier flow throughout the state. The findings significantly advance understanding of the mechanisms responsible for the rapid glacier mass loss occurring in Alaska.
| Meltwater from|
20 percent of new
to the global rise
in sea levels.
The patterns include glacier surging and spatial variations in flow related to climate. Notably, the data show that out of tens of thousands of glaciers in Alaska, only 12 are responsible for the majority of downstream ice flux. These glaciers are flowing exceptionally fast because they receive very high rates of snowfall and are not necessarily flowing fast because of tidewater retreat. (The flow speed is not the same as the melt rate; melting is strong enough at low elevations that it is outpacing the high snowfall rates.)
The data have also revealed that iceberg calving in Alaska is an important component of the statewide glacier mass budget: The volume of calved ice is 17.1 km3 – or roughly equivalent to a third of the annual net glacier mass change in Alaska.
The speed data are available for download in formats designed both for scientists and educators. Surface velocities are available for 47,880 km2 of glacier ice, which includes almost all of the state's major glaciers. See the slide show to the right for examples from the Alaska Range and the Wrangell-St. Elias Mountains.
The dataset was produced by Evan Burgess and colleagues at the University of Utah and the University of Alaska Fairbanks using ALOS PALSAR data. Detailed information on its production is available in Burgess, E. W. et al. Flow velocities of Alaskan glaciers. Nat. Commun. 4:2146 doi: 10.1038/ncomms3146 (2013).