Size and waiting time statistics of multiple sandpile cascades

Abstract

Power-law distributions are obtained for both the size and waiting times for substantially complete empirical landslide surveys. However, numerical landslide models that are based on the sandpile capture only the power-law trend for sizes, and show exponential distribution of waiting times. In this work, we incorporated the fact that landslide driving mechanisms also have power-law distributed magnitudes. We do this by representing the triggers as sandpiles themselves, driving another sandpile representing the actual landslide region. Multi-layer cascades of such sandpile-to-sandpile driving show universal power-law magnitudes of scaling exponent -0.8 and gradually fattening waiting time distributions. Our results hint to the possibility that broad interevent statistics for actual landslides are a result of multiple concurrent driving.