Change of deep subduction seismicity after a large megathrust earthquake.

Subduction zones are home to the world's largest and deepest earthquakes. Recently, large-scale interactions between shallow (0-60 km) and intermediate (80-150 km) seismicity have been evidenced during the interseismic period but also before and after megathrust earthquakes along with large-scale changes in surface motion. Large-scale deformation transients following major earthquakes have also been observed possibly due to a post-seismic change in slab pull or to a bending/unbending of the plates, which suggests the existence of interactions between the deep and shallow parts of the slab.