Fig. 5.

(a) Comparison of strain rate with occurrence rate of aftershocks of M 4 and over located in and around the aftershock area (41°N~43°N, 142.5°E~146°E) from September 27 to October 06 (JST). Light and black lines indicate variations of strain (contraction positive) and cumulative number of aftershocks. Maps of aftershocks during 10 days following the mainshock; (b) aftershocks m = 4 or more; (c) aftershocks m = 2 or more. These aftershocks are all at the depths of the subducting interface. Note that very few earthquakes m = 4 or more occur in the area where we have slow slip to satisfy the strain transient; rather, they are in the adjacent areas.