Abstract
We propose the “endo-exo” conceptual framework to account for the
varied and complex episodic landslide movements observed during
progressive maturation until collapse/stabilization. This framework
captures the interplay between exogenous stressors such as rainfall and
endogenous damage/healing processes. The underlying physical picture
involves cascades of local triggered mass movements due to fracturing
and sliding. We predict four distinct types of episodic landslide
dynamics (exogenous/endogenous-subcritical/critical), characterized by
power-law relaxations with different exponents, all related to a single
parameter ϑ. These predictions are tested on the dataset of the
Preonzo landslide, which exhibited multi-year episodic movements prior
to a final collapse. All episodic activities can be accounted for within
this classification with ϑ≈0.45±0.1, providing strong support for our
parsimonious theory. We further show that the final catastrophic failure
of this landslide is clearly preceded by an increased frequency of large
velocities corresponding to a transition to a supercritical regime with
amplifying positive feedbacks.