Thursday, February 19, 2015, 4:30PM - 5:30PM
RL-1 room 269
Projections for sea level rise in the year 2100 exceed 1 m for business-as-usual emissions, yet the projection range remains wide. Ice sheet mass loss is a primary contributor to sea level rise and, currently, the Greenland Ice Sheet contributes ~0.7 to 1.1 mm/yr to sea level (260-380 Gt/yr of ice). Roughly a third to a half of Greenland’s mass loss is due to marine-terminating outlet glacier ice discharge, which depends in large part on ice velocity. Our understanding of why and how quickly glacier motion changes, however, is limited. As recently as the late 1990s, glaciologists viewed ice sheets as relatively slow-changing (decades to centuries) features, expected to play little role in the immediate effects of climate change. The development of sophisticated remote sensing tools, however, has allowed us to discover the fast-pace (days to years) of ice sheet change, making them a direct player in current climate impacts. In this talk, we will discuss the first results to characterize Greenland outlet glacier annual velocity fluctuations on an ice-sheet-wide scale. We will also explore the developing understanding of seasonal glacier velocity patterns in the northwest, west, and southeast, the regions of the ice sheet with the highest ice discharge. Finally, we will look at recent advances in understanding the environmental and climate mechanisms driving velocity change, and ice discharge, in Greenland. Together, this work increases our understanding of ice sheet response to climate change, a key component for improving future projections of sea level rise.