The magnitude 7.3 earthquake that occurred off the coast of Fukushima Prefecture on the night of the 13th occurred in the "inside" of the sea-side plate that subducted into the land-side plate in the area along the "Japan Trench" from the Tohoku region to the offshore of the Kanto region. It is believed that.
Experts warn that the "boundary" of the plate in this area is likely to continue to have a magnitude 7 class earthquake.
The government's seismic investigation committee has stated that in the area along the "Japan Trench" from the Tohoku region to the offshore of the Kanto region, the "boundary" between the land-side plate and the sea-side plate will have a magnitude of 7 to 7.5 within the next 30 years. It is evaluated that a large earthquake will occur with a probability of 90% or more at the maximum.
The magnitude 7.3 earthquake off the coast of Fukushima Prefecture occurred in this area, but according to Naoshi Hirata of the National Research Institute for Earth Science and Disaster Prevention, who is familiar with the mechanism of the earthquake, the "inside" of the sea-side plate that sinks into the land-side plate. It seems that it occurred in, and it is a mechanism different from the big earthquake that occurs at the "boundary" of the plate.
For this reason, the probability of a major earthquake occurring at the "boundary" of the plate along the "Japan Trench" within the next 30 years will remain the same as before, with a maximum of 90% or more.
By region,
▽ east off Aomori prefecture and northern off Iwate prefecture is about 90% or more,
▽ south off Iwate prefecture is about 30%,
▽ off Miyagi prefecture is about 90%,
▽ off Fukushima prefecture is about 50%,
▽ Ibaraki It is evaluated as about 80% off the coast of the prefecture.
Mr. Hirata said, "It is important to note that the area along the Japan Trench is originally a place where seismic activity is active, and the occurrence of a large earthquake does not reduce the risk of a large earthquake 10 years ago. Although it is unlikely that a major earthquake of magnitude 9 class will occur, there is a high probability that a major earthquake of magnitude 7 class will continue to occur, so I would like you to be more prepared, such as fixing furniture. " I am.