Abstract
Recent acquisition of high-resolution satellite imagery of the Martian
surface has permitted landsliding to be studied on a global scale on
Mars for the first time. We apply the Scoops3D software package to
compute slope stability for select regions of the Martian surface,
combining calculations of slope stability with number of observed
landslides, as reported in a recently published (Crosta et al., 2018a,
b) inventory of Martian landslides, to understand controls on the global
distribution of landsliding on Mars. We find that the distribution of
landsliding does not simply follow the distribution of unstable slopes.
In particular, there is an increase in landsliding in the Tharsis Rise
area, and especially in Valles Marineris and Noctis Labyrinthus, that is
not explained by an abundance of unstable topography alone. We analyzed
for but did not find a clear local lithologic or stratigraphic control
on landslide occurrence from subsurface heterogeneities. Other
possibilities to explain the increased occurrence of landslides in the
Tharsis Rise include (1) regionally widespread Tharsis weak unit(s),
such as from interbedded ashes and lavas; (2) seismic activity related
to the Tharsis Rise’s geological activity, and (3) possible groundwater
near Valles Marineris into the Amazonian. Given the apparently young
ages of many landslide deposits in Valles Marineris (Quantin et al.,
2004), continued modern day analysis of lithologies in Valles Marineris
and observations of Martian seismicity may act to strengthen or rebut
the first two hypotheses.