Predicting Earthquakes from Sand Piles Using Self-Organized Criticality

K. Cruz and D.T. Jacobs

It has been proposed [J. Rosendahl et.al, Phys. Rev. Lett. 73, 537 (1994)] that earthquakes can be modeled by avalanches in a simple sand pile system and that increased activity before a major avalanche could be used to predict the onset of major earthquakes. With smooth glass beads forming a conical pile, we find experimentally that adding one bead at a time causes many small, and a few large, avalanches consistent with the predictions of Self-Organized Criticality. In particular, the number of avalanches of a given size is proportional to the size of the avalanche to the power (-1.43±0.05). We do not see any increased activity before a major avalanche, which is consistent with the behavior of earthquakes associated with some faults, but inconsistent with Rosendahl's results and the behavior of other faults. We also compare our results with a recent simulation that showed a characteristic time between major avalanches. This research was performed at The College of Wooster and supported by grant NSF-DMR 9619406.