CHANGES IN WIND DIRECTION AS RECORDED BY AEOLIAN LANDFORMS NEAR GILL CRATER, MARS

For billions of years wind has been the primary driving force of erosion and sediment deposition on the surface of Mars. The Arabia Quadrangle (MC-12) is an intensely cratered region from 0 – 30 degrees North and 0 – 45 degrees East. This study looked at an area within the Arabia Quadrangle near Gill Crater, approximately 1,130 km northeast of the Opportunity Rover landing site.

This study focuses on comparing surface features to better understand changes in the effect of aeolian processes and wind direction over time. Viking, HiRISE, THEMIS, and CTX data were used to examine features such as yardangs, sand dunes, and wind streaks in images spanning more than 40 years. Long, narrow yardangs indicate a paleo-wind direction from the northwest and are interpreted to be the older aeolian structures in this region compared to the wind streaks and dunes. Wind streaks are found in almost every crater and indicate wind from the northeast. Additionally, some wind streaks contain barchan dunes with slip faces that also indicate wind direction from the northeast. The wind streaks and sand dunes are interpreted to reflect the current wind direction and are evidence that regional wind direction in this area has changed since formation of the yardangs. Although no dune movement was observed at the resolution of the images, dust devil tracks south of this area indicate that aeolian processes are still active in this region.