Hubbard Glacier is the largest tidewater glacier on the North American continent. It has been thickening and advancing toward the Gulf of Alaska since it was first mapped by the International Boundary Commission in 1895 (Davidson, 1903). This is in stark contrast with most glaciers, which have thinned and retreated during the last century. This atypical behavior is an important example of the calving glacier cycle. If Hubbard Glacier continues to advance, it will close the seaward entrance of Russell Fjord and create the largest glacier-dammed lake on the North American continent in Historic times. This poster shows the measured changes in ice thickness, ice speed, terminus advance, and fjord bathymetry of Hubbard Glacier. The lower regions of the glacier have thickened by more than 80 m in the last 40 years, and the entire glacier has increased in volume by 12 km3 during that time. Ice speeds are decreasing near the calving face from a high of 16.5 m d-1 in 1948 to 11.5 m d-1 in 2001. The calving terminus advanced at a rate of about 16 m a-1 between 1895 and 1948 and accelerated to 32 m a-1 since 1948. However, since 1986, the advance of the part of the terminus in Disenchantment Bay has slowed to 28 m a-1. NOAA bathymetric data from 1978 and 1999 show that the sub-sea lee-face of the terminal moraine is advancing at an average rate of 32 m a –1; confirming the long term advance rate determined from the subaerial calving face in Disenchantment Bay.

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Maintainer: Rod March
Last update: Thursday, January 15, 2004 04:45 PM
URL: http://ak.water.usgs.gov/glaciology/hubbard//reports/2002.06_igs_poster/2002.06_igs_poster.htm