Significant changes in the dynamics of Greenland’s marine-terminating outlet glaciers within the past few years indicate a rapid and complex response of these systems to recent climatic forcing. Widespread and substantial accelerations in flow-speed of outlet glaciers in southeast Greenland have been linked to destabilization and retreat of glacier fronts triggered by thinning to flotation induced by warmer ocean temperatures. There is concern that ongoing coastal thinning in western Greenland will trigger a similar response, further threatening the stability of the ice sheet. Despite regional ice thinning and retreat, the glaciers of Greenland’s northwest coast have not yet undergone substantial acceleration. This suggests a lessened dynamic sensitivity of these glaciers to changes at the ice front than southeastern glaciers, likely due to differences in glacier geometry. To investigate the potential controls behind this contrasting behavior, we derive time series’ of front position, surface elevation, and surface thinning for 59 marine-terminating outlet glaciers in west Greenland from 2000-2009. Surface speeds are derived for several glaciers to determine sensitivity to large front retreats in this region. Using these data, we look for patterns in the relationships between retreat, thinning, acceleration, and geometric variables, such as surface slope, to determine the first-order controls on glacier sensitivity.
Data are compared to regional changes in air and ocean temperatures to assess similarities in climate forcing conditions along Greenland’s west coast. We conclude there is no direct relationship between front retreat and measured geometric parameters applicable to the entire study region. The relative importance of surface slope as a control of glacier behavior is highly variable and must be coupled to bathymetric data in order to understand and accurately model outlet glacier response to climate forcing.