Physical Sciences and Mathematics Commons^™

A Mass Balance Study Of The West Antarctic Ice Sheet, Vandy Blue Spikes

Electronic Theses and Dissertations

The present state of the West Antarctic ice sheet (WAIS) is a prime concern of science, but its large size and remote location have limited the amount of reliable data that are available for mass balance calculations. The spatial pattern of mass balance for a 100-km² portion of the WAIS is estimated by calculating the residual flux of ice through 1-km grid cells organized into a geographical information system (GIs). The input data used for this estimate include continent-scale compilations of ice thickness and snow accumulation rate measurements, and ground-based measurements of snow accumulation rate and ice velocity. The …

Ams Radiocarbon Chronology Of Glacier Fluctuations In The South Shetland Islands During The Last Glacial/Interglacial Hemicycle:Implications For Global Climate Change, Brenda L. Hall

University of Maine Office of Research Administration: Grant Reports

This award supports a two year program to produce a new reconstruction of ice extent, elevation and thickness at the Last Glacial Maximum (LGM) for the South Shetland Islands in the Antarctic Peninsula. One field season on Livingston Island will involve mapping the areal extent and geomorphology of glacial drift and determining the elevation and distribution of trimlines. In addition, ice flow direction will be determined by mapping and measuring the elevation of erosional features and the position of erratic boulders. One of the main goals of this work will be to demonstrate whether or not organic material suitable for …

Collaborative Research: Volcanic Records From The Siple And Taylor Dome Ice Cores, Antarctica, George A. Zielinski

University of Maine Office of Research Administration: Grant Reports

The primary goals of this project were to, 1) evaluate the volcanic acidity record in the Siple Dome A (SDMA) and B (SDMB) ice cores and the Taylor Dome ice core available through the sulfate time series developed by the glaciochemistry group at the University of Maine, 2) undertake a continuous scan of the SDMA core and scan specific sections in the SDMB core to locate and analyze volcanic glass to determine glass composition, and thus source eruptions for the glass and potentially for volcanic sulfate found in the same layer, and 3) evaluate specific sections containing volcanic glass in …

Antarctic Oversnow Traverse-Based Southern Hemisphere Climate Reconstruction, Paul Andrew Mayewski

Earth Science Faculty Scholarship

On 2 January 2003, the U.S. component of the International Trans Antarctic Scientific Expedition (U.S. ITASE) (Figure 1) arrived at the South Pole after completing more than 5000 km of oversnow traverses that included much of west Antarctica and a portion of east Antarctica (Figure 2). During the traverses, which were performed from 1999 through 2003, U.S. ITASE focused on collecting data that will allow the reconstruction of sub-annual scale climate variability and changes in the chemistry of the atmosphere over the last 200+ years.

ITASE is a multi-disciplinary research program supported by 19 nations and endorsed by the Scientific …

Collaborative Research: Did The Laurentine Ice Sheet Control Abrupt Climate Change?, Terence J. Hughes, James L. Fastook, David Bromwich, E. Richard Toracinta

University of Maine Office of Research Administration: Grant Reports

This is a collaborative project with the University of Maine and Ohio State University. The Principal Investigators will model the late glacial Laurentide Ice Sheet from near steady-state equilibrium at - 25,000 BP (years before present), through reversible stadial/interstadial transitions associated with Laurentide iceberg outbursts (Heinrich events 2 and 1), and across the threshold of irreversible Laurentide collapse after the last iceberg outburst at - 1 1,000 BP (Heinrich event 0). The goals are to determine if ice-sheet changes could have triggered climate changes by abrupt ice sheet change and to investigate the structure of these changes. The Principal Investigators …

Studying Byrd Glacier As A Rock-Floored Ice Stream Ending As A Calving Ice Shelf: Phase I, Terence J. Huges, Roger Hooke, James Fastook

University of Maine Office of Research Administration: Grant Reports

This award supports a one-year study of the floating part of Byrd Glacier, from its grounding line located halfway up a fjord through the Transantarctic Mountains to the end of its lateral rift zone on the Ross Ice Shelf beyond the fjord. Over this l00 km distance, the side boundary changes from rigid between the fjord sidewalls, to nearly free in the lateral rift zone, to deforming when the rifts are healed and Bryd Glacier becomes fully coupled to the Ross Ice Shelf. The stress field for these changing conditions will be calculated a using a gridpoint finite-element model for …

Crevassing And Calving Of Glacial Ice, James Patrick Kenneally

Electronic Theses and Dissertations

Calving of ice is a relatively new area of research in the still young field of glaciology. In the short time that calving has been studied, it has been mainly treated as an afterthought, with the predominant mode of thinking being that it will happen so to concern oneself with why is not important. Many studies dealt with observations of calving front positions over time vs. ice velocity in an attempt to quantify the calving rate as the difference between the two, while others have attempted to deduce some empirical relationship between calving rate and variables such as water depth …

An Interhemispheric Comparison Of The Recession Of Mountain Glaciers In The Last 150 Years, Colby Smith

Electronic Theses and Dissertations

Historical records in the Northern Hemisphere show overall glacier retreat since about AD 1860-1890. A glacial retreat of similar timing and magnitude in the Southern Hemisphere is less well established. Comparison of the timing and magnitude of glacial recession in the two polar hemispheres over the past century can elucidate mechanisms driving global climatic change. In order to determine the recession patterns of Murchison, Hooker, and Tasman Glaciers in the Southern Alps of New Zealand, geomorphic maps were constructed and recent glacial deposits were dated using lichenometry. Since the mid-to-late nineteenth century, each glacier terminus has retreated about 1.5 km. …