Icelandic ventifacts as a testbed for constraining Martian climate signatures

Ventifacts are wind-abraded rocks that are found in hot and cold deserts on Earth as well as on Mars. Their shape is modified by wind transported sediment that sandblasts the surface of the rock, forming flat facets, pits, and grooves. The orientation of these features is thought to reflect the prevailing wind direction and has been used to interpret past and current climate conditions. This work uses a field of ventifacts located in the Askja region of the Icelandic Highlands as a testbed for studying formation mechanisms of terrestrial ventifacts. This serves as a good proxy for Mars due to the similarities in cold desert environment and composition of rock type being abraded by wind.

The erosional features of 40 individual ventifacts were measured by hand in the field and 20 were rendered as 3D models and measured photogrammetrically. Comparisons between the hand and photogrammetric measurements indicate that mean feature orientation is variable throughout the field based on ventifact position as well as rock type. Statistical comparisons between the two datasets showed that while there is similarity, the photogrammetric methodologies were better equipped to measure more ventifact features at a higher level of accuracy relative to measurements made by hand. These results highlight the ability of photogrammetric methodologies to accurately characterize a ventifact field and showcases their potential in assessing existing and future imagery of ventifacts from Mars.