Antarctic Science

Physical Sciences

Formation and evolution of buried snowpack deposits in Pearse Valley, Antarctica, and implications for Mars

J.L. Heldmanna1 c1, M. Marinovaa1a2, K.E. Williamsa1a2, D. Lacellea3, C.P. Mckaya1, A. Davilaa1a4, W. Pollarda5 and D.T. Andersena4

a1 NASA Ames Research Center, Division of Space Sciences and Astrobiology, Moffett Field, CA 94035, USA

a2 Bay Area Environmental Research Institute, 560 Third St West, Sonoma, CA 95476, USA

a3 Ottawa University, Department of Geography, 60 University St, Ottawa K1N 6N5, Canada

a4 SETI Institute/Carl Sagan Center for the Study of Life in the Universe, 189 Bernardo Ave, Mountain View, CA 94041, USA

a5 McGill University, Department of Geography, 845 Sherbrooke St West, Montreal, Quebec H3A 2T5, Canada

Abstract

Buried snowpack deposits are found within the McMurdo Dry Valleys of Antarctica, which offers the opportunity to study these layered structures of sand and ice within a polar desert environment. Four discrete buried snowpacks are studied within Pearse Valley, Antarctica, through in situ observations, sample analyses, O-H isotope measurements and numerical modelling of snowpack stability and evolution. The buried snowpack deposits evolve throughout the year and undergo deposition, melt, refreeze, and sublimation. We demonstrate how the deposition and subsequent burial of snow can preserve the snowpacks in the Dry Valleys. The modelled lifetimes of the buried snowpacks are dependent upon subsurface stratigraphy but are typically less than one year if the lag thickness is less than c. 7 cm and snow thickness is less than c. 10 cm, indicating that some of the Antarctic buried snowpacks form annually. Buried snowpacks in the Antarctic polar desert may serve as analogues for similar deposits on Mars and may be applicable to observations of the north polar erg, buried ice at the Mars Phoenix landing site, and observations of buried ice throughout the martian Arctic. Numerical modelling suggests that seasonal snows and subsequent burial are not required to preserve the snow and ice on Mars.

(Online publication February 09 2012)

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