Detection of triggered deep low-frequency events from the 2003 Tokachi-oki earthquake
Abstract
We show the level of increased/decreased seismicity mapped across Japan immediately following the 2003 Tokachi-oki earthquake (Mw 8.1) of September 25, 2003 (UT) by use of the β-statistic. Significant dynamic triggering of events is found near the Nankai subduction zone 900-1400 km from the earthquake. The events are inferred to be dynamically triggered deep low-frequency earthquakes, of a type that often occur in this region. The triggering appears to be caused by the long-period oscillations of the surface waves, which may be effective in triggering fluid-related events. The region that showed the highest level of triggered events, was an area of elevated activity in the Bungo strait where a slow-slip event was in progress.
- Publication:
-
Geophysical Research Letters
- Pub Date:
- May 2005
- DOI:
- 10.1029/2005GL022539
- Bibcode:
- 2005GeoRL..3210307M
- Keywords:
-
- Seismology: Earthquake dynamics (1242);
- Seismology: Earthquake source observations (1240);
- Seismology: Earthquake interaction;
- forecasting;
- and prediction (1217;
- 1242);
- Seismology: Seismicity and tectonics (1207;
- 1217;
- 1240;
- 1242);
- Seismology: Surface waves and free oscillations