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Sensitivity Of The Antarctic Ice Sheet To Climate Change Over The Last Two Glacial/Interglacial Cycles, Brenda Hall, George H. Denton

University of Maine Office of Research Administration: Grant Reports

This project was designed to develop knowledge of the extent of the Ross Sea ice sheet during the last two glaciations and to develop a chronology for the last glacial maximum and penultimate glaciation. To this end, we had the following goals:

1) Map the extent of the Ross Sea ice sheet along the western coast of McMurdo Sound from Taylor Valley to the southern Royal Society Range.
2) Develop a radiocarbon chronology for the last glacial maximum from dates of algal mats within moraines.
3) Produce a uranium-thorium chronology to gain information on the timing of the penultimate glaciation. …

Colle Gnifetti Ice Core (Kcc) Progress Report (Year One)—Arcadia Ice Core Proposal: Initiatives On The Science Of The Human Past, Paul Mayewski

University of Maine Office of Research Administration: Grant Reports

The Colle Gnifetti glacier of the Monta Rosa Massif on the Swiss-Italian border is perfectly situated to offer insight into the intersection of environment (climate) and culture (history of the economy, political stability, pollution, disease) in medieval Europe. While ice cores previously collected at Colle Gnifetti were sampled at state-of-the-art resolution for the time, it was nevertheless impossible to differentiate annual or finer layering in the period older than 1500 A.D. The 2013 Colle Gnifetti expedition thus sought to collect a new ice core that could be analyzed using the ultra-high-resolution laser based technology developed in the Climate Change Institute’s …

Collaborative Research: Subglacial Water Intrusion In Greenland, Gordon K. Oswald

University of Maine Office of Research Administration: Grant Reports

The project's goals are:

• To analyse radio echo sounding data acquired over the Greenland Ice Sheet by the University of Kansas / CReSIS team with the objective of discriminating between frozen and thawed conditions at the bed of the ice sheet.
• To provide maps of the bed state, with the aim of making them available via the National Snow and Ice Data Centre.
• To support ice sheet modelling activities by providing information on the bed state, thus related to the temperature at the bed and the rheological conditions at the bed.
• To make available to educational establishments information on the …

Ice Core Record Of Rising Lead Pollution In The North Pacific Atmosphere, E. Osterberg, Paul Andrew Mayewski, Karl J. Kreutz, D. Fisher, Michael Handley, Sharon Sneed, C. Zdanowicz, J. Zheng, M. Demuth, M. Waskiewicz, J. Bourgeois

Earth Science Faculty Scholarship

A high-resolution, 8000 year-long ice core record from the Mt. Logan summit plateau (5300 m asl) reveals the initiation of trans-Pacific lead (Pb) pollution by ca. 1730, and a >10-fold increase in Pb concentration (1981–1998 mean = 68.9 ng/l) above natural background (5.6 ng/l) attributed to rising anthropogenic Pb emissions from Asia. The largest rise in North Pacific Pb pollution from 1970–1998 (end of record) is contemporaneous with a decrease in Eurasian and North American Pb pollution as documented in ice core records from Greenland, Devon Island, and the European Alps. The distinct Pb pollution history in the North Pacific …

Nitrate Plus Nitrite Concentrations In A Himalayan Ice Core, William Berry Lyons, Paul Andrew Mayewski

Earth Science Faculty Scholarship

The measurement of chemical constituents in glacial ice has been useful in discerning historic trends in chemical deposition and hence paleo-atmospheric records in remote areas (Thompson and Mosley - Thompson, 1981; Johnson and Chamberlain, 1981; Ng and Patterson, 1981; Neftel et al., 1982). However, delineating the sources of the deposited chemical species in question is not always straightforward. This has been especially true for nitrate. Although it is now believed that man-made emissions are responsible for a high percentage of nitrate being deposited in remote areas of the Northern Hemisphere, numerous natural sources, named and unnamed, have also contributed to …