A research group led by Yusuke Yamashita, Assistant Professor, Miyazaki Observatory, Disaster Prevention Research Institute, Kyoto University, et. al., reported the results of seismic observations of shallow slow-slip earthquakes.
A new fault model for the 1662 Hyuga-nada earthquake, which is considered to be the largest in the history of Hyuga-nada, was constructed based on the latest geophysical knowledge, such as positional information on plate boundaries using artificial seismic waves. Based on the survey results of tsunami deposits in the coastal area of Miyazaki Prefecture and tsunami inundation simulations, the fault model confirmed the possibility that the 1662 Hyuga-nada earthquake was a megathrust earthquake of M (magnitude) 7.9.
The results of this research will serve as basic materials used for disaster prevention against earthquakes and tsunamis in the national government and local governments along the coast of Hyuga-nada.
Part of the results of this research was published in the international academic journal Pure and Applied Geophysics (PAGEOPH) on December 15, 2022.