Internal avalanches in models of granular media

We study the phenomenon of internal avalanching within the context of recen tly introduced lattice models of granular media. The avalanche is produced by pulling out a grain at the base of the packing and then studying the num ber of grains to be rearranged before the packing is stable again. We find that the avalanches are long-ranged, decaying as a power law. We study the distribution of avalanches as a function of the density of the packing and find that the avalanche distribution is a very sensitive structural probe o f the system.