10.6084/m9.figshare.1011479.v1
Marco Tedesco
Marco
Tedesco
Ian C Willis
Ian
C Willis
Matthew J Hoffman
Matthew
J Hoffman
Alison F Banwell
Alison
F Banwell
Patrick Alexander
Patrick
Alexander
Neil S Arnold
Neil
S Arnold
Schematic representation of the two types of lake drainage, 'overspill drainage' and 'bottom drainage' and their different dynamic responses
IOP Publishing
2013
Abstract Supraglacial lake drainage
lake drainage
increases ice flow velocities
Greenland ice sheet
ice dynamics
Environmental Science
2013-07-16 00:00:00
Figure
https://iop.figshare.com/articles/figure/_Schematic_representation_of_the_two_types_of_lake_drainage_overspill_drainage_and_bottom_drainage_a/1011479
<p><strong>Figure 6.</strong> Schematic representation of the two types of lake drainage, 'overspill drainage' and 'bottom drainage' and their different dynamic responses.</p> <p><strong>Abstract</strong></p> <p>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.</p>