Project 4436

Global sea level fluctuations are driven by changes in the mass balance of the world's ice sheets and mountain glaciers. These fluctuations arise from either the increased discharge of ice into the oceans or through increases in snowfall over these ice masses. While satellite-derived observations of ice mass change have greatly advanced our understanding of Antarctica's contribution to global sea level, they lack ground-based constraints in many regions to fully validate the amount of ice mass change. This project will make detailed observations on the current state of Totten Glacier, East Antarctica, as well as how it has evolved over the past 50 years. These new measurements will lead to refined measurements of this outlet glacier's contribution to global sea level now and in the future.

Global sea level fluctuations are driven by changes in the mass balance of the world's ice sheets and mountain glaciers. At present, Antarctic ice loss is concentrated in regions where warm ocean water is eroding the underside of the floating ice shelves that fringe the continent. The shrinking of these ice shelves allows glaciers to discharge into the ocean at faster rates, increasing sea-level. Thus, to improve our ability to forecast future Antarctic ice loss requires a better understanding of sub ice-shelf oceanography. For this project, we made several measurements on the Totten Ice Shelf, a region undergoing change that can be accessed from nearby Casey Station. Using both fixed wing and helicopter aviation support, we made a suite of geophysical measurements. Long-term monitoring includes continuous estimates of flow speed using GPS and ice thickness using ice penetrating radar systems. By measuring how the thickness of the ice shelf changes over time we can infer ocean melting rates and then investigate how these perturbations influence glacier flow. Additionally, we made seismic measurements that will allow us to estimate ocean thickness beneath the floating ice shelf, essential for properly modeling the interactions between the ice shelf and the ocean. These efforts will supplement ongoing efforts by the global community to better constrain Antarctic's future evolution.

Global sea level fluctuations are driven by changes in the mass balance of the world's ice sheets and mountain glaciers. At present, Antarctic ice loss is concentrated in regions where warm ocean water is eroding the underside of the floating ice shelves that fringe the continent. The shrinking of these ice shelves allows glaciers to discharge into the ocean at faster rates, increasing sea-level. Thus, to improve our ability to forecast future Antarctic ice loss requires a better understanding of sub ice-shelf oceanography. For this project, we made several measurements on the Totten Ice Shelf, a region undergoing change that can be accessed from nearby Casey Station. Using both fixed wing and helicopter aviation support, we made a suite of geophysical measurements. During this year we removed long-term monitoring stations that included continuous estimates of flow speed using GPS and ice thickness using ice penetrating radar systems. By measuring how the thickness of the ice shelf changes over time we can infer ocean melting rates and then investigate how these perturbations influence glacier flow. Additionally, we made seismic measurements that will allow us to estimate ocean thickness beneath the floating ice shelf, essential for properly modeling the interactions between the ice shelf and the ocean. These efforts will supplement ongoing efforts by the global community to better constrain Antarctic's future evolution.

Global sea level fluctuations are driven by changes in the mass balance of the world's ice sheets and mountain glaciers. At present, Antarctic ice loss is concentrated in regions where warm ocean water is eroding the underside of the floating ice shelves that fringe the continent. The shrinking of these ice shelves allows glaciers to discharge into the ocean at faster rates, increasing sea-level. Thus, to improve our ability to forecast future Antarctic ice loss requires a better understanding of sub ice-shelf oceanography. For this project, we made several measurements on the Totten Ice Shelf, a region undergoing change that can be accessed from nearby Casey Station. Using both fixed wing and helicopter aviation support, we made a suite of geophysical measurements. During this year we removed long-term monitoring stations that included continuous estimates of flow speed using GPS and ice thickness using ice penetrating radar systems. By measuring how the thickness of the ice shelf changes over time we can infer ocean melting rates and then investigate how these perturbations influence glacier flow. Additionally, we made seismic measurements that will allow us to estimate ocean thickness beneath the floating ice shelf, essential for properly modeling the interactions between the ice shelf and the ocean. These efforts will supplement ongoing efforts by the global community to better constrain Antarctic's future evolution