May 2015

Modeling Water Channels Under Greenland's Ice Sheet

Christine Dow recently published a study modeling how water channels develop under the Greenland Ice Sheet after a rapid surface lake drainage. Surface lakes on the Greenland Ice Sheet can drain to the bed in a matter of hours, causing the ice to quickly speed up over the course of a day. Directly accessing the bed of the Greenland Ice Sheet is very challenging, particularly in regions where ice is more than 3000 feet thick. As a result, numerical models using data collected from field work as inputs are an ideal way to assess development of drainage systems at the base of the ice.

The work by Dow and colleagues shows that channels in inland regions of the ice sheet do not develop rapidly during lake drainage and the water instead exits the area as a turbulent water sheet. Furthermore, the modeled channels only grew slowly during the melt season and suggest that efficient drainage networks may not regulate the volumes of water input to the bed. As a result, with more meltwater produced on the surface of the ice sheet in a warming climate, the ice in the interior might maintain speeds higher than winter velocities. 

  • Dow's study can be found here.