Temporal Variation of Seismic Activity in the Region of the Pacific Coast of North-Eastern Japan

Yoshinori KATOH, Kensuke YAMAZAKI, Ryohei IKEGAMI
1981 Zisin (Journal of the Seismological Society of Japan 2nd ser )  
Temporal variation of seismic activity parameterized by the rate of earthquake occurrence, b-values, seismic energy release and randomness of interoccurrence time of shocks is investigated for three regions in the Pacific coast of north-eastern Japan over the period 1926-1978. The statistical significance of difference in b-values between before and after large earthquakes, is occasionally recognized. Change in b-values is also related to energy release in that b-values are small when the
more » ... mall when the cumulative energy release steeply increases. It is well known that, if earthquake occurrence is represented by a stationary and random process in time, the length of time interval (=z) between consecutive events is ex-
doi:10.4294/zisin1948.34.3_323 fatcat:etwvmialvrcddiqbvgmip7t4z4