This paper describes advanced finite element simulations of a geologically active and
periodically unstable 700m high underwater escarpment located in the Gulf of Mexico
that has been created by uplifting salt diapirs combined with sediment deposition. The
site's geological history, soil permeability and clay shear strength characteristics
govern current slope stability and determine the timing of any future failure. The
geological and geotechnical conditions are reported before presenting fully coupled,
large displacement, numerical simulations employing critical state formulations of the
slope's evolution over the last 600,000 years. The latter form the basis for strain
softening analyses of the pore pressure equalisation and progressive failure processes
that control current slope stability. The analyses also address the ground movement
patterns that precede instability, giving useful information for geohazard risk
assessment and early warning monitoring system design.