Academic Commons

Articles

Ice dynamic response to two modes of surface lake drainage on the Greenland ice sheet

Tedesco, Marco; Willis, Ian C.; Hoffman, Matthew J.; Banwell, Alison F.; Alexander, Patrick; Arnold, Neil S.

Supraglacial lake drainage on the Greenland ice sheet opens surface-to-bed connections, reduces basal friction, and temporarily increases ice flow velocities by up to an order of magnitude. Existing field-based observations of lake drainages and their impact on ice dynamics are limited, and focus on one specific draining mechanism. Here, we report and analyse global positioning system measurements of ice velocity and elevation made at five locations surrounding two lakes that drained by different mechanisms and produced different dynamic responses. For the lake that drained slowly (>24 h) by overtopping its basin, delivering water via a channel to a pre-existing moulin, speedup and uplift were less than half those associated with a lake that drained rapidly (~2 h) through hydrofracturing and the creation of new moulins in the lake bottom. Our results suggest that the mode and associated rate of lake drainage govern the impact on ice dynamics.

Geographic Areas

Files

Also Published In

Title
Environmental Research Letters
DOI
https://doi.org/10.1088/1748-9326/8/3/034007

More About This Work

Academic Units
Lamont-Doherty Earth Observatory
Publisher
IOP Publishing
Published Here
March 30, 2016
Academic Commons provides global access to research and scholarship produced at Columbia University, Barnard College, Teachers College, Union Theological Seminary and Jewish Theological Seminary. Academic Commons is managed by the Columbia University Libraries.