Greenland Subglacial Drainage Evolution Regulated by Weakly Connected Regions of the Bed

Authors

Matthew J. Hoffman, Fluid Dynamics and Solid Mechanics Group, Los Alamos National Laboratory
Lauren C. Andrews, Cryospheric Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt, MarylandFollow
Stephen A. Price, Fluid Dynamics and Solid Mechanics Group, Los Alamos National Laboratory
Ginny A. Catania, The University of Texas at Austin
Thomas A. Neumann, Cryospheric Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland
Martin P. Luthi, University of Zurich
Jason Gulley, University of South Florida, Tampa
Claudia Ryser, Laboratory of Hydraulics, Hydrology and Glaciology, Swiss Federal Institute of Technology (ETH)
Robert L. Hawley, Dartmouth College
Blaine Morris, Cold Regions Research and Engineering Laboratory, Hanover, New Hampshire

Document Type

Article

Publication Date

12-19-2016

Publication Title

Nature Communications

Department

Department of Earth Sciences

Abstract

Penetration of surface meltwater to the bed of the Greenland Ice Sheet each summer causes an initial increase in ice speed due to elevated basal water pressure, followed by slowdown in late summer that continues into fall and winter. While this seasonal pattern is commonly explained by an evolution of the subglacial drainage system from an inefficient distributed to efficient channelized configuration, mounting evidence indicates that subglacial channels are unable to explain important aspects of hydrodynamic coupling in late summer and fall. Here we use numerical models of subglacial drainage and ice flow to show that limited, gradual leakage of water and lowering of water pressure in weakly connected regions of the bed can explain the dominant features in late and post melt season ice dynamics. These results suggest that a third weakly connected drainage component should be included in the conceptual model of subglacial hydrology.

DOI

10.1038/ncomms13903

Dartmouth Digital Commons Citation

Hoffman, Matthew J.; Andrews, Lauren C.; Price, Stephen A.; Catania, Ginny A.; Neumann, Thomas A.; Luthi, Martin P.; Gulley, Jason; Ryser, Claudia; Hawley, Robert L.; and Morris, Blaine, "Greenland Subglacial Drainage Evolution Regulated by Weakly Connected Regions of the Bed" (2016). Dartmouth Scholarship. 2748.
https://digitalcommons.dartmouth.edu/facoa/2748