Quantifying Surface Changes on the McMurdo Ice Shelf

Abstract:

The Antarctic Ice Sheet drains through tributary glaciers along the continent’s margin, some of which merge to form buttressing ice shelves. These ice shelves play an essential role in reducing the amount of discharge from tributary glaciers by slowing their flow, thereby reducing the rate of mass transfer from land to sea. While small in comparison, McMurdo Ice Shelf is located in a critical region as it buttresses Ross Ice Shelf, whose catchment spans both East and West Antarctic Ice Sheets. Recent work has found that warm Antarctic Surface Water circulates under McMurdo Ice Shelf, resulting in a summer melt rate twice as high as the highest regions on Ross Ice Shelf, suggesting an instability of the ice shelf. However, the drivers and extent of mass loss on McMurdo Ice Shelf vary greatly across the area, and the longevity of the ice shelf as a whole is not well quantified. Here we quantify the mass transfer relationship between the McMurdo Ice Shelf and its tributary glaciers by measuring changes in surface elevation, melt, and velocity of the ice shelf and its three tributary glaciers. To quantify change, we use numerous remote sensing products and platforms, including digital elevation models (DEMs), Landsat-7, Landsat-8, ICESat-1, and ICESat-2. Our results are among the first of its kind to combine glacier dynamics and ice shelf mechanics using multiple remote sensing platforms to assess the stability of the McMurdo Ice Shelf. Here we will provide insight on the future dynamics and stability of McMurdo Ice Shelf, and those glaciers in its catchment.