SUMMARIZING OF THE LESSONS FROM THE 2016 FUKUSHIMA EARTHQUAKE AND TSUNAMI ASSESSMENT USING DATABASE

Abstract

 The present tsunami forecasting and warning system uses quantitative tsunami assessment by searching from the pre-simulated database at the time of earthquake occurrence. The database was created based on numerical tsunami simulation of assumes earthquake scenarios and operated by Japan Meteorological Agency (JMA). However, the 2016 Fukushima earthquake pointed out some problems regarding to under-estimation of tsunami in Miyagi Prefecture. The main reason for this was the accuracy of the assumed fault parameters and simulation condition used in the database. It was found that the actual strike was largely different from the assumed values. Therefore, lessons from the 2016 earthquake were summarized and tsunami characteristics in Sendai Bay was newly assessed using database as earthquake scenarios located off Fukushima and Miyagi Prefectures. As results, it was confirmed that earthquakes with magnitude of 7.0 could generated tsunamis larger than 1 m in Sendai port depending on the strike values. In addition, there are scenarios that reach tsunami warning level when considering tsunami amplitude at the Sendai port according to the newly simulated 3,168 scenarios. Therefore, accuracy of the simulated tsunami in the current forecast system based on the numerical simulation condition is important and should be improved in the future.