Date of Award

Spring 1-1-2012

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Geological Sciences

First Advisor

James P.M. Syvitski

Second Advisor

Anne E. Jennings

Third Advisor

John T. Andrews

Abstract

A record of the ice-stream history and paleoclimate of the Greenland Ice Sheet is preserved in the sediments of the Umanak System in West Greenland. This thesis documents the timing of ice retreat and the role that the West Greenland Current (WGC) played during deglaciation. Sediment cores taken along a transect of Umanak Trough capture the retreat of the Umanak Ice Stream (UIS) from its maximum extent to the inner shelf. Evidence used to determine changes in environmental conditions include foraminiferal assemblage analyses, lithofacies changes, mineralogy and IRD. Radiocarbon dates constrain the timing of these environmental changes. The UIS had retreated from the outer shelf by 14.96 cal kyr BP and post-glacial conditions were established on the mid-shelf by 11.4 cal kyr BP. Evidence of the WGC precedes lithological evidence of ice stream retreat, indicating the presence of the WGC at the shelf edge prior to initial deglaciation.

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