Seasonal Glacier Velocity on the Heimdal Glacier with a pause

The NASA/USGS Landsat 8 mission has allowed new views of the Earth’s glaciers. By tracking displacement of local surface features through the seasons on outlet glaciers from the large ice sheets, researchers from the University of Alaska, the University of Bristol, and the University of Colorado have been able to show that each glacier around Greenland has a unique pattern of flow variation through the seasons.

Seasonal variations, seen in this visualization on the lower 25 kilometers of Heimdal Glacier in southeast Greenland, are caused by a combination of processes. For Heimdal, the largest forcing for flow variation is likely the input of increasing amounts of surface melt water through the Spring and Summer, but there is also an interplay between calving of ice from the end of the glacier, flow acceleration as shown in the visualization, and thinning of the ice due to the extra stretching from the faster flow.

By measuring these changes in flow on seasonal timescales, scientists can develop a better understanding of what controls the flow of these glaciers where they meet the ocean. This understanding will improve our ability to anticipate flow responses of these systems in a warming climate.