Research Objectives:
Buried ice deposits represent an exciting and potentially far-reaching archive of atmosphere and climate on Earth extending back for many millions of years. These deposits are terrestrial analogs to widespread and young buried ice on the Martian surface as identified by recent data from Mars Odyssey.
This project will evaluate the age, origin, and climatic significance of buried ice in the western Dry Valleys region. These and other researchers have published evidence that the ice to be examined is over a million years in age, making it by far the oldest ice yet known on this planet. An alternative view is that the buried ice is more recent segregation ice produced from the in-situ freezing of groundwater. Distinguishing between these hypotheses is key to understanding Neogene climate change of Antarctica. First steps toward addressing this question have shown that glacier ice, far older than in the Vostok ice core (420,000 yrs), exists in Mullins Valley, southern Victoria Land, and that it contains the typical "saw-tooth" pattern for downcore changes in dD and d18O that so characterize climate records in late Quaternary ice cores.
The project team comprises a diverse research group with expertise in antarctic geomorphology, numerical modeling, cosmogenic dating, 40Ar/39Ar analyses, ice-core analyses, and ice-core drilling technology. The interdisciplinary research program proposes to:
+ Understand better the surface processes that permit ice preservation,
+ Test the efficacy of cosmogenic and 40Ar/39Ar analyses in dating tills above buried ice,
+ Further assess the use of cosmogenic-nuclide analyses and 40Ar/39Ar analyses of ashfall deposits to date buried ice, and
+ Use these data to help resolve the debate between "young" and "old" ice scenarios.
