Avalanche Statistics of Driven Granular Slides in a Miniature Mound

We examine avalanche statistics of rainand vibrationdriven granular slides in miniature soil mounds using experimental and numerical approaches. A crossover from powerlaw to non power-law avalanche-size statistics is demonstrated as a generic driving rate ν is increased, due to diminishing timescale separation (∼ ν) between stress buildup and release. For slowly-driven mounds, the tail of the avalanche-size distribution is a power-law with exponent −2.37 ± 0.40, significantly close to previous findings in empirical landslide data sets. The interevent occurrence time is also analyzed for slowly-driven mounds and it is found that its distribution also follows a power-law trend with exponent ≈ −1.8.