2002 Volume 111 Issue 2 Pages 192-199
We introduce a criterion for an active period of seismicity around the source region of a great interplate earthquake. It is based on stress change caused by the great earthquake. We test this criterion by applying it to the seismicity in southwest Japan before and after the 1944 Tonankai and 1946 Nankai earthquakes. We then apply it to more recent seismicity in southwest Japan and in the San Francisco Bay area. The results show that the seismicity in southwest Japan is now in transition from a quiet to active period and that the San Francisco Bay area is still in a quiet period. In other words, the probability of large earthquakes in southwest Japan is higher than it was in the preceding quiet period. Although the seismicity in the San Francisco Bay area was active in the 1980's, the probability of a large earthquake occurring is low.
