Fig. 4: Coulomb stress change computation.
From: Change of deep subduction seismicity after a large megathrust earthquake
a Focal mechanisms of intermediate and deep earthquakes that occur both before and after the Tohoku-oki earthquake (source from NIED https://www.fnet.bosai.go.jp/). The orange, 44°N latitude, and yellow, 34°N latitude, stars locate the points where we compute the Coulomb stress change due to coseismic elastic stress changes of b, c. b Blue: Coulomb stress change computed with COULOMB3 on a point located underneath Hokkaido, on the slab (lon = 140.8°, lat = 44.25°, depth = −204km, strike = 250°, dip = 26.7°, orange star in Fig. 4a) for different rake values, Orange: histogram of the rake values of all the earthquakes with latitude >42°, c Blue: same as b for a point underneath 34°N latitude on the slab (lon = 138.4°, lat = 34.70°, depth = −181km, strike = 161°, dip = 39°, yellow star in Fig. 4a); Orange: same as b) for earthquakes with latitude <35°. Here we assume a 0.4 friction coefficient.
