Granular column collapse on extra-terrestrial bodies

Frictional granular collapse is a fundamental process underlying surface evolution on Solar System bodies, including crater-wall collapse and slope failure. Laboratory experiments on granular column collapse indicate that the column aspect ratio is the dominant control parameter governing collapse behaviour. The normalized run-out length and normalized final deposit height vary approximately linearly with aspect ratio (a) for a ≤ 3, whereas for a ≥ 3 both quantities follow power-law relationships, with the scaling exponent influenced by geometry and the proportionality constant governed by the material’s internal friction angle. However, whether these scaling relations remain valid across the wide range of gravity regimes encountered in the Solar System remains unclear. Recent reduced-gravity studies [1] suggest that gravity significantly influences collapse dynamics while exerting comparatively weak control on normalized deposit geometry.

Here we investigate granular column collapse under gravity levels representative of planetary, lunar, and asteroid environments. We quantify the dependence of run-out distance, collapse duration, deposit morphology, and flow mobility on gravitational acceleration and derive corresponding scaling relations.

To this end, we combine Coupled Eulerian–Lagrangian (CEL) numerical simulations with shallow-flow theoretical modelling. The CEL formulation employs a Mohr–Coulomb plasticity model with negligible cohesion, while the shallow-flow framework provides a vertically averaged continuum description with basal friction. The resulting gravity-dependent scaling laws provide a framework linking laboratory-scale granular mechanics to planetary-scale mass-wasting processes and may aid interpretation of landslide mobility and regolith transport across Solar System bodies.

 

References

[1] Yucheng Li, Raul Fuentes (2025) Granular column collapse: Analysing the effects of gravity levels. Computers and Geotechnics, Vol. 183, 107207.