A regular study meeting was held to evaluate the possibility of a huge earthquake in the Nankai Trough, and the earthquake that observed shaking with a seismic intensity of less than 5 in Wakayama Prefecture on the 3rd of this month was "an earthquake that occurred inside the land plate. "It does not show any particular change from the scale," he said. "No particular change has been observed, which is thought to have increased the possibility of a large-scale earthquake relative to normal times." I summarized.
A study group made up of experts analyzed the data observed in and around the hypocenter area of the Nankai Trough.
On the 3rd of this month, an earthquake with a magnitude of 5.4 with an epicenter at a depth of 18 km occurred in the Kii Suido, which is the hypocenter area, and we observed shaking with a seismic intensity of less than 5 in Gobo City, Wakayama Prefecture.
Regarding this earthquake, the study group said, "It is an earthquake that occurred inside the land plate, and it is considered that it does not show any particular change in the state of fixation between the plates along the Nankai Trough due to its scale."
In addition to this, small-scale earthquakes called "deep low-frequency earthquakes" have been observed in and around the hypocenter area, but all of them are phenomena that have been observed frequently, and the study group said "Large-scale earthquakes". No particular changes have been observed that are thought to have increased the likelihood of an earthquake relative to normal times. "
Naoshi Hirata, chairman of the study group and a member of the National Research Institute for Earth Science and Disaster Prevention, said, "The epicenter of this earthquake is a little far from the upper surface of the Philippine Sea plate, where a huge Nankai Trough earthquake is thought to occur, and the scale is small. Therefore, it was concluded that there is no direct impact. However, the probability of a huge Nankai Trough earthquake occurring within the next 30 years is 70 to 80%, which is extremely high. I would like you to be fully prepared with the awareness that it is no wonder when a huge earthquake occurs. "