2016-2017 USAP Field Season
Impact of supraglacial lakes on ice-shelf stability
Dr. Douglas R MacAyeal
University of Chicago
Project Web Site:
Supporting Stations: McMurdo Station
Researchers on this project will work to establish a comprehensive theory of how ice shelves catastrophically disintegrate. The key research objectives are to characterize the energy balance and mechanical effects of natural meltwater lakes on the surface of the McMurdo Ice Shelf. The significance of the research is that it will attempt to experimentally verify a theory of ice-shelf instability recently proposed to explain the explosive break-up of Larsen B Ice Shelf in 2002. This theory holds that the filling and draining of supraglacial lakes on floating ice shelves induces sufficient flexure stress as to (a) induce upward/downward propagating fractures originating at the base/surface of the ice shelf that (b) can dissect the ice shelf into fragments of sufficiently small aspect ratio (horizontal to vertical scale ratio) as to promote extensive ice-shelf-fragment capsize during the break-up process (capsize releases gravitational potential energy and promotes explosiveness).
Field Season Overview
This event consists of two field deployments, one in October and November of 2016, and the second in January and February of 2017, with four participants deploying for each. The first deployment will focus on installing a variety of instruments at natural lake sites and rift features beyond Pegasus runway. The team will also do some site-surveying (using LiDAR and GPS), and will have UNAVCO and PASSCAL support. Access to the sites will be by snowmobile or possibly PistenBully from the VXE transition during the first deployment and by helicopter during the second deployment. The Field Safety and Training (FS&T) department will monitor the sea-ice/ice-shelf transition during the first deployment. The second deployment will focus more on site-surveying and on monitoring instruments, particularly the water flow meter. At the end of the season, all instruments will be removed, including the instrumentation installed in the 2015-16 season at the artificial basin near Pegasus.
Deploying Team Members