Research Objectives:
Scientists do not fully understand how the configuration and activity of the drainage system of the West Antarctic Ice Sheet are changing. For the following reasons, Ridge AB constitutes a key area for studying this issue:
+ While previous studies of inter–ice stream ridges in West Antarctica have revealed much about the history of the surrounding ice streams, there remains an information gap in the southern sector of the ice sheet. We believe that a targeted study of Ridge AB will reveal new information about recent changes in the configuration and activity of ice streams A and B.
+ Geologic evidence from Reedy Glacier indicates that the ice near Ridge AB was about 700 meters (m) thicker during the last glacial maximum. This helps constrain the magnitude of thinning that has occurred through the Holocene and opens the possibility of linking the history of the West Antarctic Ice Sheet to the geologic record in the Transantarctic Mountains.
We will begin by using high- and low-frequency radar systems, global positioning system surveying methods, and short (20-m) firn cores to map spatial variations of internal layering, buried crevasses, surface velocity, and accumulation rate. We will then put these diagnostic measurements into ice-flow models to infer the glacial history of Ridge AB and the surrounding ice streams. We will interpret this history in the context of the histories that are emerging from the other inter–ice stream ridges, as well as the geologic evidence from Reedy and other outlet glaciers in the Transantarctic Mountains. These explorations and analyses will enhance scientific understanding of the evolution of the drainage system of the West Antarctic Ice Sheet.
