Prediction of ignitive turbidity currents in Scripps Submarine Canyon

Swift, highly erosive continuous turbidity currents are known to be triggered in Scripps Submarine Canyon during storms. A relatively modest agitation due to edge waves can generate currents at least as swift as 1.9 m s^-1. Pantin (1979) and Parker (1982) have described a mechanism by which a turbidity current can self-accelerate by entraining sediment from the bed; Parker termed the mechanism ignition. Herein two models of steady, spatially developing turbidity currents are developed and applied to Scripps Submarine Canyon. Fairly specific predictions are obtained for the onset of ignitive acceleration, and for the downstream development of the turbidity currents. The results are in general agreement with available measurements in the same canyon. It is speculated that ignitive turbidity currents constitute a major mechanism by which sand submarine canyons are eroded, and by which sand is delivered to the abyssal plain.