Mathematics – Logic
Scientific paper
Dec 2008
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008agufm.p33b1445d&link_type=abstract
American Geophysical Union, Fall Meeting 2008, abstract #P33B-1445
Mathematics
Logic
5400 Planetary Sciences: Solid Surface Planets, 5422 Ices, 5464 Remote Sensing
Scientific paper
Pingos are hills with cores of massive injection ice, formed when pressurized groundwater forces a layer of frozen ground upwards. They are important indicators of permafrost conditions, since they require the occurrence of liquid water. In recent years, pingos have been proposed at a number of specific sites on Mars, in a variety of settings, although many of the candidate features have other proposed origins as well. The submeter resolution of the HiRISE camera allows detailed geomorphic analysis. In particular, HiRISE is capable of resolving dilational cracks expected to occur in the overburden layer of a pingo. We assess the possibility of Martian pingos with observational and theoretical constraints. Using the diffusive ice loss equations of Hudson et al. [1], we estimate that under current conditions a mid-latitude pingo could survive on the order of 106 years, long enough to be influenced by orbital variations in climate. Flexural scaling suggests that if formation conditions were similar, pingos on Mars should be similar in size to terrestrial examples. We have surveyed 1797 HiRISE images searching for fractured mounds. Several types of fractured mound are observed, concentrated in the mid-latitudes in both hemispheres. Although not an unambiguous match, the features most similar to terrestrial pingos are a variety of fractured mounds on southern-hemisphere crater floors; these usually occur in association with gullies. Flat-topped mounds in Utopia display intriguing fractures consistent with tensile failure in many cases, but do differ from terrestrial pingos in some geomorphological aspects and could originate by a different mechanism. Other fractured mounds, while occurring in the same latitude range, may form by different processes. However, the latitudinal control suggests that many of these features are in some way related to water or ice. We conclude that of the observed fractured mounds, the strongest candidates for Martian pingos are crater-floor mounds, particularly those associated with gullies; if these are pingos, this would require past liquid water in the shallow subsurface. [1] Hudson T. L. et al. (2007) JGR 112, E05016
Dundas Colin Morrisey
McEwen Alfred S.
No associations
LandOfFree
Observational and Theoretical Assessment of Possible Pingos on Mars does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Observational and Theoretical Assessment of Possible Pingos on Mars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Observational and Theoretical Assessment of Possible Pingos on Mars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1237827