Gravity and seismic investigation of a portion of the Taku Glacier, Alaska
Princeton University, NJ
The Taku Glacier is the largest glacier in the Juneau Icefield, which is located in southeastern Alaska. Recent seismic reflection surveys have found the Taku to be, at 1400 m, the deepest temperate glacier on record, although previous seismic work had suggested its depth was only 350 m. During the 2004 summer field season, as a participant in the Juneau Icefield Research Program, I conducted a gravity survey in this location of the glacier in an attempt to test these findings. I created an analytical forward model of a glacial cross section in order to solve for the Bouger anomaly, and found, from two different trials, depths of 1214+ or -89 m and 1328+ or -93 m at the deepest point of the cross section. This confirms the most recent seismic work, and indicates that the base of the glacier is approximately 300 m below sea level at the cross section measured, which is 25 km up-glacier from the terminus. The success of gravity methods to generate reliable cross sections suggests that gravity surveys could play an important role in future study on the Juneau Icefield.
Minerals Data and Information Rescue in Alaska (MDIRA)