[SSS15-P28] Early rupture process of the 2019 Off Yamagata earthquake
Keywords:Early rupture process, Source imaging technique, 2019 Off Yamagata earthquake
From the result of the source imaging for 3.6 seconds from the origin time (Fig. 1), for either fault planes, the area of large radiation strength was found in north side of the hypocenter. This area corresponds to the large slip region in the result of source inversion conducted by NIED. Two peaks of rupture strength in this area are located 4 km and 10 km northward along the strike from the hypocenter. The snapshots shown in the Fig. 2 image the highest peak of the radiation strength located about 4 km toward north from the hypocenter after 1.2 to 1.8 seconds from the origin time. The rupture in this area extends to north along the strike. Second peak in the area is located 10 km northward from the hypocenter after 3.0 seconds from the origin time.
Acknowledgements: we used the strong motion records of NIED, JMA, and Yamagata and Niigata prefectures.