9:45 AM - 10:00 AM
[SVC38-09] Intense Swarm Activity in the Vicinity of Yake-dake Volcano, Central Japan, Started in November 2018
Keywords:Yake-dake volcano, volcano tectonic earthquakes, swarm activity
Earthquakes in Series A exhibit ordinary characteristics of tectonic earthquakes with NW-SE compressional stress field and neither significant hypocenter migration nor change in source mechanism were observed during the activity. Earthquakes in Series B, however, some exhibit normal fault type stress field which is not coincide with the regional stress field.
The maximum intensity reported by JMA was less or equal to level 2 for all the events during the activity, however, instrumental seismic intensity observed nearby hypocentral area by DPRI recorded as large as level 4 for some earthquakes. Monitoring data of Yakedake volcano, that include crustal movement by GNSS and tiltmeter, geomagnetic total intensity by proton magnetometer, and ground temperature nearby summit, did not show the anomalous behavior during the swarm activity.