Experts analyzed the seismic waves on the 19th and 20th, which caused severe tremors with a seismic intensity of 6 lower and 5 higher in the Noto region of Ishikawa prefecture. It turned out that a lot of fluctuations in the cycle were included.


Experts point out, "Even if the seismic intensity is the same, the period of shaking may be different, so I hope you will continue to prepare for earthquakes."

Professor Yuki Sakai of the National Research Institute for Earth Science and Disaster Prevention, Kyoto University, who is familiar with the relationship between earthquake shaking and damage, analyzed the waveforms of seismographs installed by the National Research Institute for Earth Science and Disaster Prevention in Suzu City and Noto Town, Ishikawa Prefecture.



As a result, both the magnitude 5.4 earthquake on the 19th, which observed a seismic intensity of 6 lower, and the magnitude 5.0 earthquake, which observed a tremor with a seismic intensity of 5 upper, contained many short-period tremors of 1 second or less. I found out.

According to Professor Sakai, shaking with a cycle of less than 1 second is easy for people to feel, and furniture, roof tiles, and block walls are easily damaged.



In Suzu City, the torii gate and lanterns of the shrine collapsed due to the earthquake on the 19th, and the block wall collapsed.



On the other hand, according to Professor Sakai, in the earthquakes on the 19th and 20th, there was relatively little shaking with a cycle of 1 to 2 seconds, which is likely to cause damage such as collapse of houses.



Professor Sakai said, "Even if the seismic intensity is the same, the period of shaking will differ depending on the earthquake, and the impact on the building will also change. I want you to prepare for the earthquake. "