A research group consisting of Professor Ken Umeno and Takuya Iwata, a master's student at the Graduate School of Informatics, Kyoto University, discovered that an ionization zone anomaly had occurred just before the Kumamoto earthquake in April 2016.

 So far, in the Tohoku-Pacific Ocean Earthquake that occurred on March 2011, 3, and the offshore earthquakes of magnitude 11 or higher, such as foreshocks and aftershock, anomalies in the number of electrons in the ionization zone immediately before the earthquake were discovered. Experts disagreed whether or not an ionization zone anomaly peculiar to an inland earthquake occurred immediately before an inland earthquake with a magnitude of 7 or higher, such as the Kumamoto earthquake.

 また、熊本地震の発生2日前の4月14日午前1時頃にも、宇宙天気由来のMSTID(中規模伝搬性電離圏擾乱)による電離圏異常が観測されており、熊本地震発生直前1時間前の2016年4月16日午前0時25分頃から観測される電離圏異常が、地震由来の異常か宇宙天気によるものかは識別が困難だった。

 Therefore, the research group applied a data analysis method (correlation analysis method) that captures anomalies in the number of electrons in the ionized zone from multiple GPS satellite observation stations using only pre-earthquake data to the Kumamoto earthquake, which is an inland earthquake. Furthermore, by introducing a new evaluation index that distinguishes the anomalies in the number of electrons in the ionization zone due to space weather, the anomalies in the number of electrons in the ionization zone caused by the Kumamoto earthquake can be clearly captured from 1 hour before the occurrence of the earthquake to just before the occurrence. succeeded in.

 It is the first time to clearly distinguish between the ionospheric anomaly due to space weather and the ionospheric anomaly peculiar to the occurrence of an earthquake, and to detect the ionospheric anomaly immediately before the occurrence of an inland earthquake with a magnitude of XNUMX or higher.

 In the future, by simultaneously observing the ionospheric electron number anomaly discovered this time together with the geosphere anomaly, the mechanism of ionospheric anomaly occurrence immediately before a large earthquake due to the geosphere-atmosphere-ionosphere coupling will be further elucidated, and in the future. By detecting anomalies immediately before the occurrence of an inland earthquake of magnitude 7 or higher (predicting immediately before the earthquake) such as 1 hour or 20 minutes before the occurrence of an inland earthquake and issuing an alarm, the damage and casualties of the inland earthquake will be significantly reduced. Can be expected.

 The research results were published in the scientific journal "Journal of Geophysical Research: Space Physics" of the American Geophysical Society on February 2017, 2.

Kyoto University

Foster a free academic style based on the spirit of "self-respect for self-weight" and open up a world of creative learning.

With the motto of self-study, we will continue to maintain a free academic style that is not bound by common sense, and develop human resources who have both creativity and practical ability.We provide an inclusive learning space that allows for diverse and hierarchical choices so that students themselves can choose a solid future through valuable trial and error. […]

University Journal Online Editorial Department

This is the online editorial department of the university journal.
Articles are written by editorial staff who have a high level of knowledge and interest in universities and education.