BROADBAND SOURCE MODELS OF THE OFF MIYAGI EARTHQUAKES IN MARCH AND MAY, 2021 AND THE RUPTURE DIRECTIONS OF MODERATE-SIZED EARTHQUAKES IN THE SOURCE REGION

Abstract

The author has estimated broadband source models of the off Miyagi earthquakes in March (M_J 6.9) and May (M_J 6.8), 2021 using S-net and KiK-net strong motion records by the empirical Green’s function method. Strong motion generation areas are located at different regions of the 1978 and 2005 off Miyagi earthquakes. The short period spectral level of the two earthquakes are larger than the average of the interplate earthquakes on the Pacific plate. Rupture directions of moderate-sized interplate earthquakes in the source region estimated in this study are up dip directions which are consistent to the two earthquakes in 2021.