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2002-2003
Science Planning Summary
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Glaciology
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Dr. Julie Palais
Program Manager
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IU-185-O
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NSF/OPP
99-80434
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Station:
McMurdo Station
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RPSC POC:
Kirk Salveson
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Research Site(s):
Traverse from Byrd Surface Camp to South Pole
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U.S. ITASE: The physical properties of the U.S. ITASE ice cores
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Deploying Team Members:
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No Deployment
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Research Objectives:
The objective of this project is to examine the visual stratigraphy, physical, and structural properties of the U.S. ITASE ice cores. First, the group will examine visual stratigraphy to delineate the annual layer structure for dating purposes and to determine to as great a depth as possible, accumulation variability over the full length of a stratigraphically dated core. Wind crusts and melt layers will also be identified in each core.
Second, researchers will measure and analyze depth-density profiles. The rate of snow and firn densification depends on the rate at which the snow is deposited and the in-situ snow temperature. These data will be used to derive average snow accumulation rates for the sites where annual layer structure is difficult to decipher or where stratigraphic analysis fails altogether.
Third, they will measure the mean crystal size over the full length of a core. Since crystal growth is strongly temperature-dependent, measurements of ITASE cores will help bridge a significant data gap that exists in the mean annual temperature range, -31 to –50 degrees Centigrade. Crystal size data can also be used in conjunction with ice loads based on density profile measurements to extract mean accumulation rates for these sites where stratigraphic dating of cores proves difficult or impossible. This is likely to occur at the lowest accumulation/lowest temperature sites along the ITASE traverse routes.
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Field Season Overview:
The ITASE project team and support contractor staff traverse West Antarctica from Byrd Surface Camp (BSC) to South Pole Station. Two trains pulled by Challenger 55 Caterpillar tractors will transport personnel, instruments, and field camp equipment. Along the way, team members will collect ice cores and surface snow and ice samples, take meteorological readings, and collect radar profiles of the ice sheet. Periodically, Twin Otter aircraft will resupply the traverse team and transport samples back to Byrd Surface Camp. At the end of the traverse, the group will return to McMurdo Station where they will begin to analyze some of their samples. Other samples will be returned to their home institutions.
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