Collaborative Research: Byrd Glacier Flow Dynamics

点击翻译按钮获取中文摘要

Stearns/0944597This award supports a project to understand the flow dynamics of large, fast-moving outlet glaciers that drain the East Antarctic Ice Sheet. The project includes an integrated field, remote sensing and modeling study of Byrd Glacier which is a major pathway for the discharge of mass from the East Antarctic Ice Sheet (EAIS) to the ocean. Recent work has shown that the glacier can undergo short-lived but significant changes in flow speed in response to perturbations in its boundary conditions. Because outlet glacier speeds exert a major control on ice sheet mass balance and modulate the ice sheet contribution to sea level rise, it is essential that their sensitivity to a range of dynamic processes is properly understood and incorporated into prognostic ice sheet models. The intellectual merit of the project is that the results from this study will provide critically important information regarding the flow dynamics of large EAIS outlet glaciers. The proposed study is designed to address variations in glacier behavior on timescales of minutes to years. A dense network of global positioning satellite (GPS) instruments on the grounded trunk and floating portions of the glacier will provide continuous, high-resolution time series of horizontal and vertical motions over a 26-month period. These results will be placed in the context of a longer record of remote sensing observations covering a larger spatial extent, and the combined datasets will be used to constrain a numerical model of the glacier's flow dynamics. The broader impacts of the work are that this project will generate results which are likely to be a significant component of next-generation ice sheet models seeking to predict the evolution of the Antarctic Ice Sheet and future rates of sea level rise. The most recent report from the Intergovernmental Panel on Climate Change (IPCC) highlights the imperfect understanding of outlet glacier dynamics as a major obstacle to the production of an accurate sea level rise projections. This project will provide significant research opportunities for several early-career scientists, including the lead PI for this proposal (she is both a new investigator and a junior faculty member at a large research university) and two PhD-level graduate students. The students will be trained in glaciology, geodesy and numerical modeling, contributing to society's need for experts in those fields. In addition, this project will strengthen international collaboration between polar scientists and geodesists in the US and Spain. The research team will work closely with science educators in the Center for Remote Sensing of Ice Sheets (CReSIS) outreach program to disseminate project results to non-specialist audiences.