Award Abstract #0538097
Characterization of Lake Amundsen-Scott, S. Pole: A Ground Geophysical Program

NSF Org:	ANT Antarctic Sciences Division
Initial Amendment Date:	August 28, 2006
Latest Amendment Date:	August 28, 2006
Award Number:	0538097
Award Instrument:	Standard Grant
Program Manager:	Julie Palais ANT Antarctic Sciences Division OPP Office of Polar Programs
Start Date:	September 1, 2006
Expires:	August 31, 2010 (Estimated)
Awarded Amount to Date:	$234705
Investigator(s):	Sridhar Anandakrishnan sak@essc.psu.edu (Principal Investigator) Charles Holland (Co-Principal Investigator)
Sponsor:	Pennsylvania State Univ University Park 110 Technology Center Building UNIVERSITY PARK, PA 16802 814/865-1372
NSF Program(s):	ANTARCTIC GLACIOLOGY
Field Application(s):	0311000 Polar Programs-Related
Program Reference Code(s):	OTHR, 0000
Program Element Code(s):	5116

ABSTRACT

0538097

Anandakrishnan

This award supports a project to intensively study a subglacial Antarctic lake near the geographic South Pole using seismic and radar methods. These ground-based experiments are better suited to determine the presence of water and its thickness than are airborne methods. We hypothesize that there are two end-member explanations for this feature: either the lake is thawed, but freezing on (and likely to have been freezing on through much of the current interglacial period), or it is a frozen, relict lake for which the high basal radar reflectivity is due to intergranular water in a permafrost-like layer beneath the ice. The seismic experiment we propose is ideally suited to examine these alternatives. Intermediate cases of, e.g., a thawed saturated sedimentary base or a smooth crystalline basement layer would also be resolved by this experiment. Seismic reflections are sensitive to changes in acoustic impedance which is strongly variable with fluid content, porosity, and lithology. Water has low density relative to most rocks and low seismic velocity (and nil shear wave velocity) relative to both ice and rock. Thus, discriminating between subglacial water and subglacial rock is a task ideally suited to the seismic reflection technique. This project has significant impacts outside the directly affected fields of Antarctic glaciology and geology. The lake (either thawed or sediments with thin liquid layers around the matrix particles) will have the potential for harboring novel life forms. The experiment has the potential for expanding our information about the newest frontier in life on Earth. The collaboration between PIs in the seismic community and the marine acoustics community will foster cross-disciplinary pollination of ideas, techniques, and tools. In addition to traditional seismic techniques, new methods of data analysis that have been developed by acousticians will be applied to this problem as an independent measure of lake properties. We will train students who will have a wider view of seismology than would be possible in a traditional ocean acoustics or traditional geoscience seismology program of study.

PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH

LE Peters, S Anandakrishnan, CW Holland, H Horgan, DE Voigt. "Discovery of a deep lake near the geographic South Pole," Geophysical Research Letters, v.35, 2008, p. L23501.

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