Alpine Glacial Features of Mars

Abstract

EVIDENCE of past alpine glacial erosion in the south polar region of Mars appears in two photographs taken by Mariner 9 in early 1972. Although no glacial remnants show up in either photograph, the aretes, U-shaped valleys, and other glacial evidences closely resemble the ice-free features of the Cascade Mountains in the northwestern United States. Continental glaciers that exist near the Martian poles have been described previously^1,2. Axial precession and changes in the orbital eccentricity are thought to be the cause of climatic variations on the Martian surface. Thus, the alpine glaciers responsible for the erosion of the features described herein could have recently disappeared because of a warming trend that did not eliminate the polar ice caps.