Characteristic small-earthquake sequence off Sanriku, northeastern Honshu, Japan
Article first published online: 14 JUN 2002
Copyright 2002 by the American Geophysical Union.
Geophysical Research Letters
Volume 29, Issue 11, pages 38-1–38-4, June 2002
How to Cite
Characteristic small-earthquake sequence off Sanriku, northeastern Honshu, Japan, Geophys. Res. Lett., 29(11), doi:10.1029/2001Gl014632, 2002., , and ,
- Issue published online: 14 JUN 2002
- Article first published online: 14 JUN 2002
- Manuscript Accepted: 14 MAY 2002
- Manuscript Revised: 30 APR 2002
- Manuscript Received: 25 DEC 2001
- characteristic earthquake;
- repeating earthquake;
- seismic coupling
 We found eight similar earthquakes of M4.8 regularly occurring from 1957 to 1995 on the plate boundary off Sanriku, northeastern Japan. The mean recurrence interval of the events is 5.35 years and its standard deviation is only 0.53 years. These events have the same focal mechanisms of low-angle thrust fault type and their source sizes are estimated to be around 1 km. The slip of each event is comparable to the cumulative amount of relative plate motion in the inter-seismic period. Thus, these events are probably caused by repeating slip at a small but strong asperity surrounded by creeping zone on the plate boundary. The next event was expected to occur by the end of November 2001 with 99% probability and actually M4.7 event occurred on November 13, 2001.