[HDS15-P01] Estimating topography before the volcanic sector collapses using tsunami survey data with numerical simulations
Keywords:sector collapse, topography, tsunami , numerical simulation
The Oshima-Oshima Tsunami, which is the subject of many previous studies, was first simulated to evaluate how tsunami heights changed during the simulation as the topographic conditions changed. It was found that tsunami height was especially sensitive to the collapsed volume and frictional acceleration acting on the collapsed material; however, observed tsunami heights could be reproduced with high accuracy using proper conditions of frictional acceleration for the scenarios even they were not exact. A minimum requirement for the collapsed volume of the observed tsunami height was introduced and quantitatively evaluated using the results of numerical tsunami simulations. The requirements for the collapses of Komagatake Mountain and Unzen-Mayuyama Mountain, for which there is not much quantitative data or many previous studies, were estimated to be approximately 1.2 and 0.3 km3, respectively.