SEGJ Technical Conference

Estimation of Shallow Velocity Structure using MASW at High-Intensity Seismic Stations of the 2018 Hokkaido Eastern Iburi Earthquake

Abstract The 2018 Hokkaido Eastern Iburi earthquake caused severe building damages around the epicentral area. In this area we carried out the observations of the multichannel analysis of surface waves (MASW) at five sites, including four strong motion stations (K-NET: Oiwake, Mukawa, KiK-NET: Oiwake, JMA: Shikanuma), to evaluate the effect of the shallow underground velocity structure on the strong motion records of the main shock. Phase velocities estimated in frequency range from 5 to 40Hz for these sites are much different from each other. It can be, consequently, confirmed that the strong ground motion of the main shock were characterized strongly by the shallow velocity structure at the site.