Power-law distribution of landslides in an experiment on the erosion of a granular pile

Experimental aspects of self-organized criticality are investigated in a micro-model exhibiting mass displacements involving material flow in three dimensions. By watering a ridge-shaped pile made of a granular mixture we observe micro-landslides whose size distribution indicates a power-law dependence with an exponent tau close to 1. To obtain a more detailed description of the geometrical changes in the profile of the eroding ridge we also determine the temporal scaling of the height correlation function and the distribution of the local velocities.