Numerical modelling of the late stage of subduction zone transference after an accretion event

The resumption of subduction of an oceanic plate at a contact with a docked island (continental) margin is modelled numerically in 2D. The mechanical properties of the crustal and mantle rock masses are treated with visco‐plastic rheologies where the viscosities are described by a dynamic power law phenomenologically accounting for the transient texture evolution of the deforming rock masses. The study is limited to the extreme case of a fluid weakened lithosphere characterized by a uniform effective yield stress. At a constant push of 8 cm a −1 , the shear zones split the oceanic slab into blocks at the contact with the island. At a moderate yield stress ( σ Y  < 80 MPa) and normal relaxation rate of viscosity, subduction resumes in less than ca 1 Ma. High σ Y  = 100 MPa leads to the island edge bending. A detached block of the island is subducted after the plunge of the oceanic plate reverses.