Surface meltwater that reaches the base of an ice sheet creates a mechanism for the rapid response of ice flow to climate change. The process whereby such a pathway is created through thick, cold ice has not, however, been previously observed. We describe the rapid (<2 hours) drainage of a large supraglacial lake down 980 meters through to the bed of the Greenland Ice Sheet initiated by water-driven fracture propagation evolving into moulin flow. Drainage coincided with increased seismicity, transient acceleration, ice-sheet uplift, and horizontal displacement. Subsidence and deceleration occurred over the subsequent 24 hours. The short-lived dynamic response suggests that an efficient drainage system dispersed the meltwater subglacially. The integrated effect of multiple lake drainages could explain the observed net regional summer ice speedup.

Item Type:	Refereed Article
Keywords:	ice; surface water; climate change; drainage; fracture propagation; glacial lake; ice flow; ice sheet; lake; meltwater; seismicity; acceleration; article; climate change; deceleration; glacier; Greenland; ice sheet; lake; priority journal; Arctic
Research Division:	Earth Sciences
Research Group:	Physical geography and environmental geoscience
Research Field:	Physical geography and environmental geoscience not elsewhere classified
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the earth sciences
UTAS Author:	King, MA (Professor Matt King)
ID Code:	81951
Year Published:	2008
Web of Science® Times Cited:	378
Deposited By:	Geography and Environmental Studies
Deposited On:	2013-01-11
Last Modified:	2014-07-30
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