Estimating earthquake-induced submarine landslide hazards in the Ulleung Basin, East Sea

Abstract

Lagre numbers of submarine landslides have been found in the Ulleung Basin, East Sea, Republic of Korea. Slides-debris flows-turbidities are most common. It is considered that they may be caused by the seismic activities near or at the active faults. For this reason, natural hazards and disasters prevention-related researches are currently underway in Korea to find active faluts (or the existence of active faults) and in this regard, studies on the geological hazards and disaster measures are being conducted. The studies are mainly focused on the mechanical and numerical characteristics of earthquake-induced submarine landslides and debris flow-tsunami potential. The determinstic method is one of potential methods to solve the submarine landslide hazards, in terms of slope stability. We have analyzed gemorphological and geotechnical characteristics in the East Sea. In order to examine the past and future landslide hazards, fault and landslide mappings are undergoing. In this presentation, we will propose a new model considering the wetting and yield stress reductional phenomena in the analysis of the high-mobile mass movements. In particular, a comparison of earthquake-induced and landslide-induced tsunamis will be highlighted. In summary, three research contents will be consisted of (i) earthquake-triggering submarine mass movements and tsunamic hazards, (ii) linkage between fault activation from subaerial to subaqueous structural line, and (iii) development of early warning system.