Measuring and Modeling Geosphere-Cryosphere Interactions in Southern Alaska

Sauber, Jeanne; Muskett, Reginald; Luthcke, Scott; Rolands, David
NASA Goddard Space Flight Center University of Alaska; Jeanne.M.Sauber-Rosenberg@nasa.gov

In the region of southern Alaska that includes the Malaspina and Bering Glacier systems, large ice fluctuations occur directly above a shallow main thrust zone associated with subduction of the Pacific-Yakutat plate beneath continental Alaska. We have used recent glacier elevation change studies [Muskett et al., 2008, 2009] and GRACE mascon-derived estimates of glacier mass fluctuations [Luthcke et al., 2008] to estimate ice mass variations from 1988 - 2007 for this region. Also, we calculated surface displacement rates, incremental stresses, and change in the fault stability margin of the solid Earth associated with these ice mass variations. In 2002-2006, for instance, the predicted displacement rates of the solid Earth due to average annual changes in ice loads were up to 20 mm/yr for the vertical and 3 mm/yr for the horizontal. In this same region, the predicted tectonic uplift rate in the same region is predicted to be 0-12 mm/yr and the horizontal rates 10-35 mm/yr.