Greenland is melting, but how fast?
There are a number of possible controls on outlet glacier velocity, including:
These two possibilities suggest alternative environmental controls on the ice dynamics. In the case of the Zwally effect, there is likely to be a strong atmospheric control, as warmer temperatures result in greater melt intensities. In the case of reduced resistive forces at the glacier grounding line, oceanographic controls are more significant (e.g. Hanna et al., 2009; Holland et al., 2008; Nick et al., 2009)
The GLIMPSE project aims to measure the changes occurring in the Greenland ice sheet margins and identify the processes driving these changes. This will enable us to improve current models to better predict the contribution of Greenland ice to sea level rise and freshwater input to the North Atlantic.
|Figure 7: The Zwally Effect - Surface melt water draining to the bed of the Greenland Ice Sheet may lubricate ice-rock interface, fasciliating fast ice flow. Source: Zwally, et al., (2002), Surface Melt-Induced Acceleration of Greenland Ice-Sheet Flow, Science, 297 (5579), 218 - 222 doi: 10.1126/science.1072708|