[SCG63-P04] 3-D Numerical Simulation of Island Arc Deformation Due to Steady Plate Subduction
Keywords:island-arc trench system, steady plate subduction, free-air gravity anomaly
In this study, we develop a 3-D numerical model based on elastic-viscoelastic dislocation theory and compute lithospheric displacement rates in the island arc-trench system caused by steady slip on a plate interface, which has a convex bend toward the island arc along the trench axis. Computed results show that the island arc lithosphere significantly subsides around the bend, where horizontal extension parallel to the trench axis is observed. This result suggests that the slip vectors that have the direction away from the bend along the trench in the overriding plate results in mass deficit around the bend and subsidence of the island-arc lithosphere.