Articles | Volume 9, issue 1
The Cryosphere, 9, 103–108, 2015
The Cryosphere, 9, 103–108, 2015

Brief communication 15 Jan 2015

Brief communication | 15 Jan 2015

Brief Communication: Sudden drainage of a subglacial lake beneath the Greenland Ice Sheet

I. M. Howat1, C. Porter2, M. J. Noh1, B. E. Smith3, and S. Jeong1 I. M. Howat et al.
  • 1School of Earth Sciences and Byrd Polar Research Center, Ohio State University, Columbus, Ohio, USA
  • 2Polar Geospatial Center, University of Minnesota, St. Paul, Minnesota, USA
  • 3Polar Science Center, Applied Physics Lab, University of Washington, Seattle, Washington, USA

Abstract. We report on the appearance of a 2 km wide, 70 m deep circular depression located 50 km inland of the southwestern margin of the Greenland Ice Sheet that provides the first direct evidence for concentrated, long-term storage, and sudden release, of meltwater at the bed. Drainage of the lake may have been triggered by the recent increase in meltwater runoff. The abundance of such lakes and their potential importance to the ice sheet's hydrologic system and flow regime remain unknown.

Short summary
In the summer of 2011, a large crater appeared in the surface of the Greenland Ice Sheet. It formed when a subglacial lake, equivalent to 10,000 swimming pools, catastrophically drained in less than 14 days. This is the first direct evidence that surface meltwater that drains through cracks to the bed of the ice sheet can build up in subglacial lakes over long periods of time. The sudden drainage may have been due to more surface melting and an increase in meltwater reaching the bed.