[M-IS04] Interdisciplinary studies on pre-earthquake processes

[MIS04-P04] Hindcast and forecast of earthquake activity using ULF magnetic data around the station based on ROC results during 2001-2010.

*服部 克巳^1,2,3、金子 柊⁴、野田 洋一⁴、吉野 千恵¹、韓 鵬⁵ (1.千葉大学大学院理学研究院、2.千葉大学環境リモートセンシング建久センター、3.千葉大学災害治療学研究所、4.千葉大学大学院融合理工学府、5.南方科学技術大学)

キーワード：hindcast and forecast、ULF magnetic data、ROC、optimal parameter

There is concern about an earthquake directly below the Tokyo metropolitan area. According to the Cabinet Office, Japan, there is a 70% probability of an earthquake directly below the Tokyo metropolitan area occurring within the next 30 years. Earthquake disaster prevention measures are more focused on post-event response. The main pre-earthquake countermeasures are to strengthen buildings and structures against earthquakes, and there is no system for active evacuation based on prior information before a disaster occurs, as in the case of heavy rainfall disasters in the weather, even though the occurrence of an event is uncertain. In the case of the torrential rain disaster, the decision makers were appropriately informed of crisis avoidance actions and were able to manage the risks. This is due to the experience of the decision makers and the accuracy of the advance information. In the case of torrential rain disasters in Japan, typhoons and torrential rains occur somewhere every year, accumulating knowledge and insight into the spatiotemporal events before and after the event. Observation technology has also advanced, and it is now possible to grasp the current situation through radar images and other means. What about earthquakes? The government's view on prior information, except for long-term forecasts, has not been established. The time scale of large earthquakes that cause damage does not match the time scale of human life, and knowledge has not been accumulated efficiently. The preparation for the earthquake directly under the Tokyo metropolitan area and the direction of future earthquake disaster mitigation research (short-term forecasting research) will be discussed using the ULF geomagnetic field variation. ULF magnetic changes have been confirmed as earthquake precursor using statistical analysis of significant correlation and ROC for the period of 2001-2010. ROC investigation can provide optimal parameters to forecast sizable earthquake. In the presentation, the hindcast and the forecast results with optimal parameters will be demonstrated.