Seasonal ice flow patterns as indicators of subglacial hydrology on the Greenland Ice Sheet

Thursday, 17 December 2015: 15:25
3002 (Moscone West)
Twila A Moon, University of Oregon, Eugene, OR, United States, Mark A Fahnestock, University of Alaska Fairbanks, Fairbanks, AK, United States, Ted Scambos, National Snow and Ice Data Center, Boulder, CO, United States, Ian Joughin, Univ Washington, Seattle, WA, United States, Michiel van den Broeke, Utrecht University, Institute for Marine and Atmospheric Research, Utrecht, Netherlands and Marin J Klinger, National Snow and Ice Data Center, CIRES University of Colorado, Boulder, CO, United States
Improvements in satellite coverage of the Greenland Ice Sheet have supported a substantial increase in the spatial and temporal resolution of surface velocity measurements. Previously, with seasonal TerraSAR-X satellite measurements of marine-terminating glaciers across the western and southeastern coasts, we identified three dominant and distinct seasonal velocity patterns. Two patterns likely indicate differences in the development of the subglacial hydrologic system, one suggesting development of efficient subglacial drainage during the summer melt season and the other without. Using this framework, we are now taking advantage of a new velocity record we created from Landsat 8 OLI imagery, which allows for better sampling across space and time, to examine local and regional variations in ice sheet surface velocity. Readily measurable, ice velocity holds strong potential as a proxy for understanding changes in subglacial hydrology, which is much more difficult to observe. We investigate seasonal velocity behavior from glacier termini toward the ice sheet interior and among separate glacier systems across the Greenland Ice Sheet as a way to understand changes in ice motion and ice sheet hydrology.