Undergraduate Honors Theses

Thesis Defended

Spring 2017

Document Type

Thesis

Type of Thesis

Departmental Honors

Department

Geological Sciences

First Advisor

Gifford Miller

Second Advisor

Charles Stern

Third Advisor

John Andrews

Fourth Advisor

Benjamin Teitelbaum

Fifth Advisor

Anne Jennings

Abstract

The Petermann Ice Tongue, located in the northwest region of Greenland, has experienced large caving events since 2010. It is one of the few remaining ice tongues and or ice shelves still present in Greenland. The Petermann Glacier and its ice tongue are important to study as little is known about their glacial history since the deglaciation that likely began in the early Holocene. Through analyzing two cores, 18GC in Hall Basin and 003TC/41GC/003PC in the Petermann Fjord, in conjunction with prior analysis of the HLY03-05GC core in Hall Basin (Jennings et al., 2011), a relative glacial history of the Petermann Glacier is proposed. The mineralogy, grain size, and mass magnetic susceptibility were analyzed at 10-centimeter increments within the cores. A distinct lithofacies of laminated clays with almost no ice rafted debris (IRD) was observed in both the cores, as well in the HLY03-05GC core previously studied (Jennings et al., 2011). Based on knowledge of modern sub ice shelf sediments this laminated clay unit is tentatively interpreted to represent a sub ice shelf environment. The laminated clay unit is seen at the base of 18GC, overlain by a bioturbated mud unit. This transition from the laminated clay to bioturbated mud within 18GC is proposed to be representative of opening of Nares Strait around 9200 cal years BP. Within the composite core, 003TC/41GC/003PC, a shift from coarser grained sediment to the laminated clay unit is proposed to reflect the advance of the ice tongue site in the Petermann Fjord. This history of the Petermann Glacier contributes to the ongoing research being conducted in order to further understand the processes at work since the onset of the retreat of the Greenland Ice Sheet.

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