For the first time, the government's Earthquake Research Committee has published an evaluation of active faults in the sea area for large earthquakes that occur along the coast of the southwestern part of the Sea of ​​Japan from the Chugoku region to northern Kyushu.


There are 37 active faults, and the probability of a major earthquake with a magnitude of 7 or more within the next 30 years is about 10% overall.

The government's Earthquake Research Committee has so far announced the scale and probability of earthquakes targeting major active faults and trench-type earthquakes nationwide.



This time, we announced for the first time the evaluation results of active faults with a length of 20 km or more in the sea area, targeting the southwestern part of the Sea of ​​Japan from off Tottori prefecture to off Nagasaki prefecture.



According to the latest research, a total of 37 active faults were found,


▽ 11 in the "eastern area" off the coast of Tottori prefecture and eastern


Shimane prefecture, and 17 in the "central area" off the western part of Shimane prefecture and off the northern part of Yamaguchi prefecture. ,


▽ There are nine in the "western area" off the northern coast of Kyushu and off the northwestern coast of Kyushu.



As a result of estimating the probability that a major earthquake with a magnitude of 7 or more will occur in each region within the next 30 years,


▽ 3% to 7% in the eastern region,


▽ 3% to 6% in the central region,


▽ 1% in the western region It is estimated to be

3%, and


8% to 13% as a whole.



However, since survey data is limited in the sea area, the intervals between past earthquakes include large errors, and there is a possibility that there are active faults that cannot be evaluated at a depth of 5 to 10 km. It is pointed out that further investigation and research are desired because the tsunami may arrive in a short time.

Naoshi Hirata, chairman of the Earthquake Research Committee and a member of the National Research Institute for Earth Science and Disaster Prevention, said, "Tsunami may occur in an earthquake that occurs in the sea area, so please be careful. It is important that the latest research has realized that it was difficult to evaluate the activity of earthquakes so far. "He said that he would evaluate active faults in other sea areas in the future.

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