Seismic observations of a deep-seated landslide site in Sambagawa Belt

―Case study at Toujiyama, Otoyo, Kochi, Japan

Abstract

  To reveal the mechanism of deep-seated catastrophic landslides (DCLs) by large subduction-zone earthquakes and inland earthquakes in accretionary complexes, including metamorphic rocks, we undertook seismic observations and detailed geological mapping at Toujiyama, Shikoku. In this area, DCLs have been repeatedly formed by large earthquakes and heavy rainfall. As a result, seismic amplification characteristics and geological causes were obtained in this slope.