2002-2003 Science Planning Summary

Geology & Geophysics

Dr. Scott Borg
Program Manager


NSF/OPP 01-25842
Station: McMurdo Station
RPSC POC: Karla College
Research Site(s): Dry Valleys

Multiple isotope analyses of soil sulfate and nitrate in the Antarctic Dry Valleys
Dr. Huiming Bao

Deploying Team Members: See Marchant (GO-054-O)
Research Objectives: The breakthrough that makes this project possible is the recent discovery of mass-independent oxygen-isotopic composition for sulfate and nitrate in Dry Valley soils which show that atmospheric deposition has contributed a significant amount of sulfate and nitrate to cold-desert soils over time.

The goal of this project is to quantify atmospheric deposition of sulfate and nitrate in the Dry Valleys region. Researchers will generate the first quantitative model describing the origin, distribution, and post-depositional alteration of atmospheric sulfate and nitrate in Dry Valley soils. In addition to testing the hypothesis that landforms in the Dry Valleys have been stable for millions of years, the group's results will provide a valuable reference for quantitative soil development in hyper-arid deserts elsewhere on Earth and on Mars.

Field Season Overview:
Nine team members will participate in two collaborative projects with combined logistical support:

- Dr. David Marchant (GO-054-A)

- Dr. Huiming Bao (GO-051-O)

Project team members will erect camps in the Olympus and Asgard Ranges. With helicopter support, researchers will map moraines and collect soil samples. Soil excavations will be filled in and the desert pavement replaced, a technique that allows for rapid surface recovery. Researchers will also collect volcanic ash in the McKelvey Valley region and measure ancient sub-glacial meltwater channels at the head of Wright Valley.

Supported by the University NAVSTAR Consortium (UNAVCO) and support contractor personnel, two team members will acquire high-precision elevation data for up to 50 sites within the western Dry Valleys region. The data will be used to produce high-resolution, one-meter contour maps of selected study areas and to provide control for analyses of cosmogenic data. Rock and soil samples will be returned to the investigators’ home institutions for analyses.