[M-GI28] [EE] Data assimilation: A fundamental approach in geosciences

[MGI28-P01] Data assimilation for optimal estimation of frictional parameters and prediction of afterslip in the 2003 Tokachi-oki earthquake

*加納 将行¹、宮崎 真一²、石川 洋一³、伊藤 耕介⁴、平原 和朗² (1.東京大学地震研究所、2.京都大学理学研究科、3.海洋研究開発機構、4.琉球大学理学部)

キーワード：Data assimilation, Afterslip, Frictional parameters, GNSS

A wide variety of fault slips at plate subduction zones are considered to reflect the spatial heterogeneities of frictional parameters. Thus, it is important to estimate the frictional parameters from geophysical observations. In addition, these estimated frictional parameters contribute to compute a realistic spatio-temporal evolution of fault slips. For this purpose, we have developed a technique to optimize frictional parameters and to predict a spatio-temporal evolution of slip based on an adjoint data assimilation method [Kano et al. 2010; 2013] and applied to the afterslip data in the 2003 Tokachi-oki earthquake [Kano et al. 2015]. In this presentation, we review these studies, and discuss the problems and the future plan for challenges of earthquake forecasting.