Modeled flow speed (colour) for Pine Island Glacier and its floating ice shelf. Speed is also shown with 50 m a-1 white contours for values up to 500 ma-1. [click to enlarge]
Analysis of rapidly changing Antarctic ice shelves using ERS and GLAS altimetry, RADARSAT SAR interferometry and 3-D ocean modeling
Summary
This project focuses on the rapidly changing Peninsula and Pine Island Ice Shelves. In the first part of this project, we produced a velocity map for the Larsen-C ice shelf. Because the bed topography for the adjoining ice sheet is far better known, we have concentrated our modeling efforts on Pine Island Glacier, where we have coupled an ice shelf model to a model for the grounded ice sheet developed under another project. We used inverse methods to solve for the flow law parameters on the ice shelf [Joughin et al., 2009]. Before using a more complicated ocean model, we developed simple parameterizations for melting beneath the ice shelf with which to determine the sensitivity of the coupled ice shelf/stream/sheet system to melt rate. Our initial results show that by increasing ice shelf melt, we are able to speed up and thin the ice stream in good agreement with observed velocity and elevation changes. Based on this success, we are developing model experiments to assess Pine Island Glacier’s contribution to sea level over the next century.
