[S-CG40] Science of slow-to-fast earthquakes

[SCG40-P08] Data Assimilation for Fault Slip Monitoring and Short-Term Prediction of Spatio-Temporal Evolution of Slips: Application to the 2010 Long-Term SSE in the Bungo Channel, Japan

*加納 将行^1,2、田中 優介¹、佐藤 大祐²、飯沼 卓史²、堀 高峰² (1.東北大学理学研究科、2.海洋研究開発機構)

キーワード：Slow Slip Event、Data Assimilation、Frictional Properties、GNSS

Monitoring and predicting fault slip behaviors in subduction zones is essential for understanding earthquake cycles and assessing future earthquake potential. We developed a MCMC-based data assimilation method for fault slip monitoring and short-term prediction of slow slip events (SSE). We applied to the GNSS data during the 2010 Bungo Channel SSE in southwest Japan. The observed geodetic data were quantitatively explained using a physics-based model with data assimilation. Next, we investigated short-term predictability by assimilating observation data within limited periods. Without prior constraints on fault slip style whether slip is fast or slow, observations solely during slip acceleration predicted the occurrence of a fast slip; however, the inclusion of slip deceleration data successfully predicted a slow transient slip. With prior constraints to exclude unstable slip, the assimilation of data after slow slip event occurrence also predicted a slow transient slip. This study provides a tool using data assimilation for fault slip monitoring and prediction based on real observation data.