Acceleration and spatial rheology of Larsen C Ice Shelf, Antarctic Peninsula

The disintegration of several Antarctic Peninsula ice shelves has focused attention on the state of the Larsen C Ice Shelf. Here, we use satellite observations to map ice shelf speed from the years 2000, 2006 and 2008 and apply inverse modeling to examine the spatial pattern of ice-shelf stiffness. Results show that the northern half of the ice shelf has been accelerating since 2000, speeding up by 15% between 2000 and 2006 alone. The distribution of ice stiffness exhibits large spatial variations that we link to tributary glacier flow and fractures. Our results reveal that ice down-flow from promontories is consistently softer, with the exception of Churchill Peninsula where we infer a stabilizing role for marine ice. We conclude that although Larsen C is not facing imminent collapse, it is undergoing significant change in the form of flow acceleration that is spatially related to thinning and fracture. Citation: Khazendar, A., E. Rignot, and E. Larour (2011), Acceleration and spatial rheology of Larsen C Ice Shelf, Antarctic Peninsula, Geophys. Res. Lett., 38, L09502, doi: 10.1029/2011GL046775.