TC The Cryosphere TC The Cryosphere 1994-0424 Copernicus Publications Göttingen, Germany 10.5194/tc-8-2047-2014 Glacier-like forms on Mars Hubbard B. https://orcid.org/0000-0002-3565-3875 1 Souness C. 1 Brough S. https://orcid.org/0000-0002-6581-6081 1 Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, UK 05 11 2014 8 6 2047 2061 Copyright: © 2014 B. Hubbard et al. 2014 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://tc.copernicus.org/articles/8/2047/2014/tc-8-2047-2014.html The full text article is available as a PDF file from https://tc.copernicus.org/articles/8/2047/2014/tc-8-2047-2014.pdf

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<sup>−1</sup>; 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.

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