ANALYSIS OF PHYSICAL PROPERTIES FOR SMALL LANDSLIDES IN ARAM-ARES CHANNEL, MARS

An east-west channel (located at 341°E and 3°N) connects Aram Chaos to Ares Valles. The valley is approximately 80 km long, 12 km wide, and 1.5 km deep. The north wall of the valley (south facing) has a series of slope failures or landslides that form lobate aprons covering the valley floor. We studied the formation of the six most distinct landslides in this valley. Each landslide was characterized using gridded MOLA topography from JMARS, including area, drop height and run out distance. These relatively small landslides have areas ranging from 5.6 to 55 km². Landslide aprons cover approximately 45% of the valley length. Their aprons run out ~ 10 km, often covering the entire width of the valley floor. Drop height was measured using both maximum and minimum estimates due to resolution limits of the topography. Drop height ranged from 1200 to 2200 meters. Using the drop height and run out distance, we determine the coefficient of friction and maximum velocity for each landslide using previously established landslide equations based on physical properties. The coefficient of friction for the landslide events ranged from 0.05 to 0.17, which corresponds to a maximum landslide velocity of 117 m/s² to 172 m/s². The two largest landslides, also located the furthest east, had the lowest coefficients of friction (~0.05). While the smaller landslides located in the middle, had the highest calculated coefficients of friction (~0.17). The variations in the coefficients may be due to landslides size, relative size, or possible volatile or ice content. Future work will use higher resolution topographic data sets and more detailed geomorphic mapping to examine these relationships.