3 research outputs found
Glacier-like forms on Mars
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
Landscapes of polyphase glaciation: eastern Hellas Planitia, Mars
<p>The mid-latitudes of Mars host numerous ice-related landforms that bear many similarities to terrestrial ice masses. This collection of landforms, termed viscous flow features (VFFs), is composed primarily of H<sub>2</sub>O ice and shows evidence of viscous deformation. Recent work has hypothesised that VFFs are the diminishing remains of once larger ice masses, formed during one or more previous ice ages, and the landscape therefore records evidence of polyphase glaciation. However, debate persists concerning the former extent and volume of ice, and style of former glaciations. The accompanying map (1:100,000 scale) presents a geomorphic and structural assessment of a glacial landscape in eastern Hellas Planitia, Mars. Here, we present a description of the features identified, comprising four geomorphic units (plains, lobate debris apron, degraded glacial material, and glacier-like form) and 16 structures (craters, moraine-like ridges, flow unit boundaries, arcuate transvers structures, longitudinal surface structures, ring-mold craters, terraces, medial moraine-like ridges, raised textured areas, flow-parallel and flow-transverse lineations, crevasses and crevasse traces, and ridge clusters).</p