Coseismic Coulomb stress change of Japan Mw9.0 earthquake and triggering of aftershocks

In order to learn more about the stress triggering of Japan Mw9.0 earthquake, we calculate the coseismic Coulomb stress change produced by main-shock on subsequent earthquake events based on two finite element models, providing by Shao et al. and Hayes of USGS. Meanwhile, using different aftershock catalogs from GCMT and F-net and given a variable effective friction coefficient, a triggering percentage can be obtained. The preliminary study suggests that 60% to 65% aftershocks fall into the red or increased area of Coulomb stress change. There are 58% to 70% aftershock nodal planes showing a stress increased state, which indicates existing stress triggering between main shock and aftershocks. It is more obvious that the huge Mw9.0 earthquake causing local tectonic stress field readjusting is responsible for subsequent occurrence of a large number of aftershocks. © 2015 ejge.