Martian climatic events on timescales of centuries: Evidence from feature morphology in the residual south polar ice cap

• Published in: Geophysical Research Letters
• Main Authors: Byrne, Shane, Ingersoll, Andrew P.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Geophysical Union 2003
• Subjects: Ice cap
• Online Access: https://doi.org/10.1029/2003GL017597

Flat-floored, quasi-circular depressions on the southern residual cap of Mars have been observed to expand rapidly. Analysis of the size distribution combined with modeling of the growth process yields information about the ages of these features. We report on properties of a population of these features within a selected study area. We find a narrow size distribution that indicates a common formation time and a finite period during which new features were forming. Some change in environmental conditions occurred during this period, which we date at several Martian decades to centuries ago depending on modeled growth rates. We report on THEMIS data that reveals the nature of larger features outside our study area. Underlying water ice is exposed on the flat floors of these depressions near the outer walls. These features may record more than one growth phase, indicating that conditions conducive to growth may switch on and off with characteristic timescales of Martian centuries. © 2003 by the American Geophysical Union. Received 23 April 2003; accepted 5 June 2003; published 9 July 2003. This work was made possible by funding from the Mars data analysis and Mars fundamental research programs. Thanks to the MOLA team and THEMIS (especially Greg Neumann) for such great access to their data and Ken Tanaka and Eric Kolb who provided the outline of the residual cap. Thanks to Norbert Schorghofer for prompting the size measurements and providing comments. Published - 2003GL017597.pdf