Bistability and hysteresis in tilted sandpiles

We show that tilting a model sandpile that has dynamic disorder leads to bi stability and hysteresis at the angle of repose. Also the distribution of l ocal slopes shows an interesting dependence on the amount of tilt weakly ti lted sandpiles retain the quasicontinuous distributions of the steady state while large tilt makes the distribution more discrete with local slopes cl ustered round particular values. These observations are compared with recen t experimental results on avalanche shapes. We also consider the percolatio n of local instability and anomalous roughening of the sandpile surface.