Skip to main content
U.S. flag

An official website of the United States government

North-south geological differences between the residual polar caps on Mars

January 1, 2000

Polar processes can be sensitive indicators of global climate, and the geological features associated with polar ice caps can therefore indicate evolution of climate with time. The polar regions on Mars have distinctive morphologic and climatologic features: thick layered deposits, seasonal CO2 frost caps extending to mid latitudes, and near-polar residual frost deposits that survive the summer. The relationship of the seasonal and residual frost caps to the layered deposits has been poorly constrained, mainly by the limited spatial resolution of the available data. In particular, it has not been known if the residual caps represent simple thin frost cover or substantial geologic features. Here we show that the residual cap on the south pole is a distinct geologic unit with striking collapse and erosional topography; this is very different from the residual cap on the north pole, which grades into the underlying layered materials. These findings indicate that the differences between the caps are substantial (rather than reflecting short-lived differences in frost cover), and so support the idea of long-term asymmetry in the polar climates of Mars.

Publication Year 2000
Title North-south geological differences between the residual polar caps on Mars
DOI 10.1038/35004528
Authors P. C. Thomas, M. C. Malin, K.S. Edgett, M. H. Carr, W.K. Hartmann, A.P. Ingersoll, P.B. James, L. A. Soderblom, J. Veverka, R. Sullivan
Publication Type Article
Publication Subtype Journal Article
Series Title Nature
Index ID 70022909
Record Source USGS Publications Warehouse