The 20th annual Symposium will be held on Thursday, April 23, 2009.

Mechanisms of Glacial Ablation at Linnébreen, Svalbard, Norwegian Arctic
Norris 100, 2:15 PM

Kristen  Mitchell,   '09 13
   Major: Geology
   Hometown: Glenview, IL

Sponsor(s): Thomas Wilch
Support: National Science Foundation Research Experience for Undergraduates, Hampshire College

Abstract: 
Glacier surface lowering, meltwater discharge, and meteorological conditions were monitored during the summer 2008 melt season at Linnébreen, an Arctic cirque glacier. Linnébreen is located on the western edge of Spitsbergen, the largest island in the Svalbard archipelago in the Norwegian Arctic.

Nine glacier surface lowering measurements were taken at eight centerline locations over the course the 2008 ablation season (mid July through mid August). These measurements were correlated to meteorological observations to better understand surface lowering dynamics of the glacier. Snow loss from Linnébreen was converted to a meltwater equivalent to estimate the volume of water lost from the glacier for each day. This volume was then compared to measured discharge in the adjacent meltwater stream.

The highest ablation occurred during late July, corresponding to periods of higher temperatures and solar radiation. These 2008 results are consistent with historical records. Photo analysis reveals an average glacier retreat rate of 17 m/yr since 1936 with a rate of 41 m/yr during the past 14 years. Annual measurements indicate average surface lowering of 1.13 meters for the 2008 melt season, and a negative net balance of .34 meters, less negative than most years. Temperature and direct sunlight were inferred to be the main agents of surface lowering of Linnébreen. Continued observation is essential to better evaluate the controls on surface lowering and negative mass balance of Linnébreen. The glacial mass loss at Linnébreen is consistent with other proxy climate records in the high Arctic, which indicate accelerated warming in this region.

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