Failure of Marine Deposits and their Redistribution by Sediment Gravity Flows

SedFlux simulates the fill of sedimentary basins, and can be used to examine the location and attributes of sediment failure on continental margins and the runout of their associated sediment gravity flows. Numerical experiments show how the evolving boundary conditions of sea-level fluctuations, floods, storms, tectonic and other relevant processes control the rate and size of slope instabilities. By tracking deposit properties (pore pressures, grain size, bulk density, porosity), a finite-slope factor-of-safety analysis of marine deposits examines failure potential. A decider routine is used to determine whether the failed material will travel down slope as turbidity current or a debris flow. Examples provided insight into: (i) why fjords dominated by turbidity current deposition often contain debris flow deposits; (ii) how glaciated margins prograde seaward through shallow failures of low yield strength material; and, (iii) how large-scale basin subsidence can control the onset of canyon formation across continental slopes.