[SVC37-P06] Estimation of pressure source occurring volcanic crustal deformation with FEM considering topography
Keywords:FEM, Mt.Ontake, GNSS, InSAR, ALOS-2
Based on this background, we developed a crustal deformation calculation system that incorporates the Finite Element Method (FEM) that divides elastic bodies into minute meshes and calculates displacement for each mesh. As a result, it became possible to analyze taking model topography and underground structure into account. In this study, we compare the deformation source estimated using the FEM with the deformation source estimated by the conventional method. In this presentation, we mainly examined the eruption of Mt.Ontake in Nagano Prefecture in 2014. We detected about 10cm crustal deformation in the crater and its surroundings with InSAR analysis by ALOS-2 satellite on the eruption (Yamada et al., 2014). Based on this observation result, we estimated the deformation source with a model assuming a conventional semi-infinite homogeneous elastic body, and we obtained the result that the almost vertical crack opened 45 cm. However, since the topography of the region where the crustal deformation was observed by this eruption is steep and it is thought that the deformation is also influenced by the topography, in this presentation we report the results of comparison of the conventional estimation and the estimation considering the influence of the topography.