Dr. Devon Burr

December 19, 2006

"Pingos on Earth and Mars"

The objective of this proposed work is quantitative morphological and contextual characterization of terrestrial pingos with application to pingo-like forms (PLF’s) on Mars. The goal of the work is the development of criteria to enable correct identification of pingos on Mars. Pingos are 100-m-scale, massive ice-cored (and clathrate-cored?) mounds. They grow from near-surface or deeper groundwater, often maintaining a subpingo (liquid) water lens during growth, and then collapse to leave recognizable relict forms. Found only in permafrost terrain, extant pingos are indicative of massive ground ice beneath a thin overburden and periglacial conditions. Collapsing or relict pingos indicate the past existence of ground ice, permafrost, and periglacial conditions. Pingos may also be associated with subsurface faults, a suggestion that will be investigated explicitly in this proposed work through mapping of faults from high-resolution geologic and geophysical data beneath pingos fields in Alaska. Correct identification of pingos on Mars would contribute to our understanding of the contemporary and historic distribution of Martian ground ice, surficial/near-surface water processes, and climate and climate change. It may also improve our understanding of deep groundwater movement, indicate subsurface structure, and provide sites for future astrobiological exploration. In this work, we will characterize terrestrial pingos in three ways: 1) quantitative description of Alaska pingo morphology; 2) refinement and application of a statistical technique to describe these pingos’ collective spatial distribution; and 3) mapping of near-surface faults and development and application of a statistical technique to quantitatively assess the correlation between Alaskan pingos and faults. We will then apply the morphological characterizations derived from the Alaskan pingos to PLF’s on Mars both described in the literature and compiled under previous and ongoing Planetary Geology and Geophysics (PGG) and Mars Data Analysis Program (MDAP) research. The results of this work will be assessment of Martian PLF’s and a significantly improved ability to correctly identify and classify pingos on Mars. These results in turn will improve our collective ability to identify sites of past or present near-surface ground ice (or clathrate?), near-surface or deeper groundwater, permafrost terrain, possible subsurface faults, and potential sites for future astrobiological exploration. As PLF fields are near possible landing sites for two future landed missions, this work will aid in understanding these two sites and the results from those missions.