Date of Award

Summer 8-2022

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Doctor of Philosophy (PhD)

Department

Earth Sciences

Advisor

Paul Andrew Mayewski

Second Committee Member

Andrei V. Kurbatov

Third Committee Member

Kirk A. Maasch

Additional Committee Members

Sean Birkel
Jefferson C. Simões

Abstract

The research presented in this dissertation focuses on glaciochemical records of trace elements, major ions, and stable water isotopes from three mountain regions: the Antarctic Peninsula, the Central Chilean Andes, and South Georgia Island.

The first section reports a significant increase in U concentration over 27 years on Detroit Plateau, Antarctic Peninsula. U concentrations in the ice core increase by as much as 102 between the 1980s and 2000s, accompanied by increased variability in recent years. The U concentration increase coincides with expanded open pit mining in the Southern Hemisphere, most notably Australia. Since other land-source dust elements do not show similar large concentration increases, and since the increased U concentrations are enriched above average levels in the Earth's crust, the source of U is attributed to human activities rather than atmospheric circulation changes.

The second section of this dissertation presents a 100-year, continuous, sub-annually dated ice core record from Tupungatito glacier, Central Chilean Andes. This section documents change over time of atmospheric pollution in Central Chile and a significant change in atmospheric pollutant concentrations coincident with anthropogenic activities in this region. Moreover, Cd, As, Pb, Cu, and Ag concentrations exhibit enriched values far in excess of natural levels over the last century, with the increases beginning around the 1930’s.

Lastly, the third section of thesis dissertation focuses on a short glaciochemical record from a snow/firn core collected on South Georgia Island. This reconnaissance study provides information about snow chemistry and preservation of environmental records at an elevation of 850 m a.s.l. The results presented in this section help to determine the feasibility of future deep ice coring on South Georgia Island.

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