Cliff collapse is an active geomorphological process acting at the surface of the Earth
and telluric planets. Recent laboratory studies have investigated the collapse of an initially
cylindrical granular mass along a rough horizontal plane for different initial aspect ratios
a = H_i/R_i, where H_i and R_i are the initial height and radius, respectively. A numerical
simulation of these experiments is performed using a minimal depth-integrated model
based on a long-wave approximation. A dimensional analysis of the equations shows that
such a model exhibits the scaling laws observed experimentally. Generic solutions are
independent of gravity and depend only on the initial aspect ratio a and an effective
friction angle. In terms of dynamics, the numerical simulations are consistent with the
experiments for a less than 1. The experimentally observed saturation of the final height of the
deposit, when normalized with respect to the initial radius of the cylinder, is accurately
reproduced numerically. Analysis of the results sheds light on the correlation between the
area overrun by the granular mass and its initial potential energy. The extent of the
deposit, the final height, and the arrest time of the front can be directly estimated from the
"generic solution" of the model for terrestrial and extraterrestrial avalanches. The
effective friction, a parameter classically used to describe the mobility of gravitational
flows, is shown to depend on the initial aspect ratio a. This dependence should be taken
into account when interpreting the high mobility of large volume events.

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