Nankai Trough Study Group "No particular changes observed" 18:11, May 12
The regular study group, which evaluates the possibility of a huge earthquake in the Nankai Trough, summarized the view that "no particular change has been observed."
The study group made by experts analyzed the data by holding a regular meeting again by exchanging documents due to the influence of the new coronavirus.
In the hypocenter region of the Nankai Trough and its surroundings, a small earthquake called a "deep low frequency earthquake" was observed in the eastern part of Shikoku between the 17th and 27th of last month. It means that slight changes were observed in multiple "strain gauges" and tilt data.
This is due to the "short-term slow slip", in which the boundary of the plate deep in the hypocenter region moves slowly over a relatively short period.
Also, the crustal movements that have been observed in the western Kii Peninsula and the eastern part of Shikoku since last year are stagnant, and in the Shima Peninsula, slight crustal movements that are different from the previous trends are observed. .
It is thought that this is due to the "long-term slow slip" that the plate boundaries move slowly each year, and both are phenomena that have been repeatedly observed. No particular changes have been observed that are considered to have a relatively higher probability of occurrence than in normal times. "