"Recent" Mars Polar Resurfacing Event Suggested by Small Impact Cratering Record

Details "Recent" Mars Polar Resurfacing Event Suggested by Small Impact Cratering Record "Recent" Mars Polar Resurfacing Event Suggested by Small Impact Cratering Record

Dec 2003

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003agufm.p32b..07m&link_type=abstract

American Geophysical Union, Fall Meeting 2003, abstract #P32B-07

Physics

5465 Rings And Dust, 6225 Mars

Scientific paper

The cratering record of the northern and southern polar layered deposits (PLD) reveals at least two major Amazonian resurfacing events with possible global atmospheric implications. The lower portion of the SPLD reveals a population of remarkably shallow 1-5 km impact craters, estimated to have accumulated mostly about 30-100 million years ago.(Koutnik, et al, 2002). Younger accumulations of SPLD generally overlie these older SPLD in the higher elevations, but themselves exhibit only a sparse population of fresh-to-moderately degraded primary impact craters generally less than 1 km in diameter. Many of these small craters exhibit well-preserved rims, and even a few ejecta blankets. The freshest (270 meter diameter) includes its own smaller secondaries. Hence, it is clear that the impact process into Martian polar ice closely follows the patterns of rock impacts elsewhere. This smaller-diameter population of relatively well-preserved impact craters implies one or more "recent" resurfacing events, and that topic is the focus of this investigation. From a comprehensive search of MOLA data, and of the MOC/NA and THEMIS-VIS images, we describe the abundance, distribution and morphology of smaller impact craters over the entire SPLD. A surprisingly young cratering age (and thus the estimated time since the "recent" resurfacing event) is required if the primary impact flux scales with the lunar model. However, constraints inferred from the extensive secondary crater population surrounding the 23 km diameter McMurdo primary crater (Schaller, et al, this meeting), must also be considered when assessing how recently the small crater resurfacing event took place. Furthermore, the extreme paucity of any impact craters on the NPLD would seem to place additional burdens on any simple unifying hypothesis of global atmospheric resurfacing. We outline several possible local ways to reconcile these seemingly conflicting implications including separate hemispherical polar resurfacing processes, or some unrecognized elevation-dependent process of recording and or retaining small impact craters. References [2] Koutnik, M., S. Byrne, and B.C. Murray (2002) JGR, 107, (E11).

Affiliated with

Also associated with

No associations

Rating

"Recent" Mars Polar Resurfacing Event Suggested by Small Impact Cratering Record 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 "Recent" Mars Polar Resurfacing Event Suggested by Small Impact Cratering Record, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and "Recent" Mars Polar Resurfacing Event Suggested by Small Impact Cratering Record will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1425678