Articles | Volume 8, issue 6
Research article
05 Nov 2014
Research article |  | 05 Nov 2014

Glacier-like forms on Mars

B. Hubbard, C. Souness, and S. Brough

Abstract. More than 1300 glacier-like forms (GLFs) are located in Mars' mid-latitudes. These GLFs are predominantly composed of ice–dust mixtures and are visually similar to terrestrial valley glaciers, showing signs of downhill viscous deformation and an expanded former extent. However, several fundamental aspects of their behavior are virtually unknown, including temporal and spatial variations in mass balance, ice motion, landscape erosion and deposition, and hydrology. Here, we investigate the physical glaciology of martian GLFs. We use satellite images of specific examples and case studies to build on existing knowledge relating to (i) GLF current and former extent, exemplified via a GLF located in Phlegra Montes; (ii) indicators of GLF motion, focusing on the presence of surface crevasses on several GLFs; (iii) processes of GLF debris transfer, focusing on mapping and interpreting boulder trains on one GLF located in Protonilus Mensae, the analysis of which suggests a best-estimate mean GLF flow speed of 7.5 mm a−1; and (iv) GLF hydrology, focusing on supra-GLF gulley networks. On the basis of this information, we summarize the current state of knowledge of the glaciology of martian GLFs and identify future research avenues.

Short summary
We address the dynamic glaciology of glacier-like forms (GLFs) on Mars, over 1300 of which are located in the planet's midlatitude regions. We present case studies to gain insight into (i) the former extent of GLFs, (ii) GLF motion and surface crevassing, (iii) GLF debris transfer (suggesting a best-estimate surface velocity of 7.5 mm/a over the past 2 Ma), and (iv) putative GLF surface hydrology. Finally, we present several possible research directions for the future study of Martian GLFs.