Elastoplastic Deformation in a Wedge-Shaped Plate Caused by a Subducting Seamount

M. Ding[1], J. Lin[2]
[1]MIT/WHOI Joint Program in Oceanography, Cambridge, MA, USA
[2]Woods Hole Oceanographic Institution, Woods Hole, MA, USA

We used COMSOL Multiphysics 4.3 to simulate the 2D elastoplastic deformation and plastic strain in a wedge-shaped plate above a subducting interface. The modeling results reveal that a pair of conjugate normal faults would first appear in the thinner part of the plate. Subsequently, a second pair of conjugate thrust faults would form in the thicker part of the plate. The duration of the seamount movement required for these faults to cut through the entire plate is larger for deeper seamounts, greater dipping angles of the plate, and for the Mohr-Coulomb than for Von Mises criteria. Our models provide a quantitative way to investigate the time-dependent lithospheric deformation and fault formation processes during seamount subduction.