Session S7 - Self-Organized Criticality.
FOCUS session, Wednesday afternoon, March 14
Room 609, Washington State Convention Center
We present a directed avalanche model describing an unloading sand box. The surface becomes unstable above a critical local slope. The system is driven by lowering a retaining wall at the bottom of the slope. For specific toppling rules in this model, the avalanche propagation is related to the space-time configurations of one dimensional surface growth dynamics, and belongs to the Kardar-Parisi-Zhang universality class. From this, we derive various exact scaling exponents for the avalanche cluster distributions. This work is somewhat related to recent results for a Stochastic Directed Sandpile Model by Paczuski et al and Kloster et al where the avalanche dynamics is related to Edwards-Wilkinson type surface growth. This research is supported by the National Science Foundation under grant DMR-9985806.