2002-2003 Science Planning Summary

Geology & Geophysics

Dr. Scott Borg
Program Manager

GO-058-O

NSF/OPP 99-80452
Station: McMurdo Station
RPSC POC: Joni English
Research Site(s): Pecora Escarpment, Beardmore Glacier, Allan Hills, LaPaz Icefield

The Antarctic search for meteorites (ANSMET)
Dr. Ralph P. Harvey
Case Western Reserve University
Department of Geological Sciences
rph@po.cwru.edu
http://www.cwru.edu/affil/ansmet

Deploying Team Members: Carlton C Allen . Philip A Bland . Andy Caldwell . Nancy Chabot . Diane E Di Massa . Dean B Eppler . Ralph P Harvey . Dante Lauretta . Scott Messenger . Jamie L Pierce . John W Schutt . Linda C Welzenbach . Sunita Williams
Research Objectives: Since 1976, ANSMET (the Antarctic Search for Meteorites program) has recovered more than 10,000 meteorite specimens from locations along the Transantarctic Mountains. Antarctica is the world's premier meteorite hunting ground for two reasons:

First, although meteorites fall all over the globe at random, the likelihood of finding a meteorite is enhanced if the background material is plain and the accumulation rate of terrestrial sediment is low. This makes the East Antarctic Ice Sheet the perfect medium.

Second, along the margins of the sheet, ice flow is sometimes blocked by mountains, nunataks, and other obstructions. This exposes slow-moving or stagnant ice to the fierce katabatic winds, which can deflate the ice surface and expose a lag deposit of meteorites (a representative portion of those that were sprinkled throughout the volume of ice lost to the wind). When such a process continues for millennia, a spectacular concentration of meteorites can be unveiled.

It is important to continue recovering antarctic meteorites because they are the only currently available source of new, non-microscopic extraterrestrial material. As such, they provide essential "ground truth" about the composition of asteroids, planets, and other bodies of our solar system. ANSMET recovers samples from the asteroids, the Moon and Mars for a tiny fraction of the cost of returning samples directly from these bodies.


Field Season Overview:
During the 2001-2002 field season, ANSMET's main field party visited the Meteorite Hills region near the headwaters of the Darwin Glacier. Systematic searching at this site resulted in the collection of 740 meteorites. This season will extend systematic searches to regions visited only sporadically last year, including the nearby Finger Ridges, where three meteorites were recovered in 2000-2001.

From McMurdo Station, the systematic search party will travel by LC-130 aircraft to Beardmore South Camp. From there they will make at least three overland traverses to Goodwin Nunataks and MacAlpine Hills where they will conduct systematic searches for meteorites. Mid-season Twin Otter flights will re-supply the team, remove trash, empty fuel drums, and transfer personnel. At the end of the season, researchers will make a day trip by helicopter to the Allan Hills region.

A second field party dedicated to high level reconnaissance will be ferried to and from South Pole Station by LC-130 flights. Twin Otter flights will support put-ins, re-supply, and camp moves of this team in the Pecora/La Paz region. Samples will be returned to the home institution for analysis.