Spatiotemporal characteristics of basal resistance to ice flow in the West Antarctic Ice Sheet from satellite observations and numerical modeling

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Dr. Brent Minchew has been granted an NSF Earth Science postdoctoral fellowship to carry out a research and education plan at the British Antarctic Survey. His research will focus on the West Antarctic Ice Sheet (WAIS) with the goal of quantifying how much resistance to glacier flow the bed applies and how that resistance varies in space and time. WAIS is the only large ice sheet whose bed is significantly below sea level, making it potentially unstable in warming climates. Current knowledge of the physics of glaciers and geological evidence suggest that WAIS is capable of rapid collapse, which, in its current configuration, could lead to several meters of sea level rise. Recent studies provide evidence that a collapse may be underway but the plausible timescales over which a collapse can occur remain uncertain. In order to understand these timescales, which are largely governed by what happens at the bed, and to elucidate the salient mechanical properties of glacier beds, Dr. Minchew will use a combination of observed ice flow velocities and numerical ice flow models to infer the basal resistance to ice flow in several WAIS glaciers and ice streams. The observations were collected at an unprecedented rate over a long timespan and with complete spatial coverage of several areas of fast-flowing ice. When used to constrain numerical ice-flow models, these observations allow for estimates of the variability of basal resistance in space and time that will provide a more thorough understanding of how glacier flow is coupled to environmental forcing. These results will test current assumptions concerning the mechanical properties of the bed, inform more detailed models of basal mechanics, and contribute to the development of predictive models of WAIS and its influence on sea level rise. Dr. Minchew's research will foster international collaborations and, importantly, will include an education and public outreach component. International collaboration is essential for understanding the potential near-term consequences of climate change. Through this fellowship, Dr. Minchew will have the opportunity to work closely with esteemed glaciologists at the British Antarctic Survey, gaining experience that he will return to the US upon completion of the fellowship. Throughout the fellowship, while at home and abroad, Dr. Minchew will work to enhance the public's awareness of the role of WAIS in the climate system, the implications of climate change for WAIS, and how changes in WAIS affect people and societies around the world.