– Science Management for the US Contribution to the International Trans Antarctic Scientific Expedition (1998-2003) P.A. Mayewski
This proposal presented the primary objectives, rationale and organization for US ITASE activities in West Antarctica. 11 scientific projects were organized under this structure. In addition US ITASE SMO coordinated workshops, data collection, and outreach activities (in concert with the Museum of Science – Boston). More than 150 scientific products (abstracts, papers, and reports) have resulted thus far from US ITASE research.
NSF-0096299 – ITASE Glaciochemistry (1999-2004) P.A. Mayewski and L.D. Meeker
This project focused on the analysis of major ions recovered from firn/ ice cores collected on US ITASE traverses through West Antarctica. Glaciochemical series covering 200-1000+ years provide proxy records of atmospheric circulation and chemical species source strength. To date 33 peer-reviewed papers have been published or are in review from this work (for detailed citations please see NSF Fastlane for this project). Two MSc theses and part of a PhD (not yet complete) have resulted from this work.
OPP-0196441 – ITASE Mass Balance and Accumulation Rates (1999-2004) G.S. Hamilton
The objectives of this project are to understand spatial differences in the rate of ice sheet thickness changes in West Antarctica and to determine the magnitude and causes of spatial variations in snow accumulation rate. During four field seasons, 16 mass balance marker sites were installed and resurveyed, numerous shallow cores were collected, and ~5000 km of continuous high-precision elevation profiles were surveyed simultaneously with ground penetrating radar stratigraphy. Results from the mass balance marker sites indicate that large portions of the interior West Antarctic Ice Sheet are close to steady state, with no large ongoing changes in ice thickness. Sites that are close the regions of enhanced flow show ongoing thinning of about a decimeter per year. Accumulation rates are found to be highly variable over short spatial scales. Causes of the variability are tied mainly to local surface topography. The effect of this variability on mass balance calculations was investigated. Four papers were published or are in press in peer-reviewed journals; several other manuscripts are in preparation. The data provided the basis for on PhD thesis examining spatial gradients in accumulation rate (Blue Spikes, PhD awarded December 2003).
Background for this Proposal
The International Trans Antarctic Scientific Expedition (ITASE) is a multi-national, multi-disciplinary field research program with the broad aim of understanding the recent environmental history of Antarctica (Mayewski and Goodwin, 1997; see ITASE Science and Implementation Plan). Primary emphasis is placed on the last ~200 years of the record although US ITASE typically samples significantly longer periods that include the classic period of the Little Ice Age into the Medieval Warm Period. A minimum of the last 200 years was selected because it covers the onset of major anthropogenic involvement in the atmosphere and the end of the Little Ice Age. Further, the Tambora volcanic eruption (AD1815) provides an excellent stratigraphic marker for age calibration of 200-year records. In addition, overland snow traverse programs can logistically handle the collection and transport of several 200-year long ice cores.
Participants at a workshop held in Baltimore (May, 1996) agreed (see US science and Implementation Plan) that the US contribution to the International Trans Antarctic Scientific Expedition (US ITASE) would be comprised of individual science proposals that would each compete on their own merit. The same format is being utilized for this current round of US ITASE proposals. It was also decided that a lead proposal should be submitted to the Office of Polar Programs to assist in planning and organization of US ITASE activities. That proposal was successful and funds for the US ITASE Science Management Office (SMO) (1998-2003) supported the PI (P.A. Mayewski, no salary) and a part-time staff member (4 months/year) to assist in communication, coordination and outreach, and student participation in field activities. Funds also supported domestic and foreign travel, and office supplies.