The 2018 Hokkaido Eastern Iburi Earthquake (1)
On September 6, 2018 at 03:07 (JST), there was an M6.7 earthquake at a depth of 37 km in the central and eastern Iburi regions, Hokkaido. In addition to the seismic intensity 7 at Atsuma town, Hokkaido, and the seismic intensity 6 Upper at Abira town and Mukawa town, Hokkaido, the seismic intensity ranging from 6 Lower to 1 was observed in the area extending from Hokkaido region to a part of Chubu region. Japan Meteorological Agency announced an Earthquake Early Warning (Alert) for this earthquake at 03:08:12.6, 7.3 sec after the first detection of seismic wave. This event occurred within the continental plate. The focal mechanism (CMT solution) showed a reverse fault type with a compression axis in an ENE-WSW direction. After this event there occurred earthquakes in the surrounding area of the recent event, about 30 km length in NS. The seismic activity after the recent event is rather higher than those of the past inland or coastal earthquakes in Japan with the same magnitude or greater (refer to Fig.2-10).
The reported damage caused is 41 fatalities, 691 injured persons, 394 totally-, 1016 severely-collapsed houses and so on (as of October 5 at 18:00 (JST), Fire and Disaster Management Agency).
Japan Meteorological Agency named this earthquake as "the 2018 Hokkaido Eastern Iburi Earthquake."
Sapporo Regional Headquarters, Muroran Local Meteorological Office and Asahikawa Local Meteorological Office dispatched JMA Mobile Observation Team (JMA-MOT) to the seismic intensity observation points and the surrounding area observing 5 Upper or larger in order to survey the changes of their observing environments by the event and performed the investigation of the damage situation for the check of the consistency with the JMA seismic intensity table. Also in order to assist the disaster response of the local governments, Sapporo Regional Headquarters, Sendai Regional Headquarters, Nagoya Local Meteorological Office and Maebashi Local Meteorological Office dispatched JETT to Hokkaido Government, and Muroran Local Meteorological Office dispatched JETT to Iburi general subprefectural bureau.
Damage situation due to "the 2018 Hokkaido Eastern Iburi Earthquake" is shown in Table 1-1. The number of earthquakes ordered in the maximum intensity for the intensity 1 or over and the number of earthquakes in time are shown in Table 1-2.
Japan Meteorological Agency
[Evaluation of the 2018 Hokkaido Eastern Iburi Earthquake (October 12, 2018)]