Japan Geoscience Union Meeting 2023

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[J] Oral

S (Solid Earth Sciences ) » S-VC Volcanology

[S-VC31] Active Volcanism

Mon. May 22, 2023 10:45 AM - 11:45 AM 303 (International Conference Hall, Makuhari Messe)

convener:Yuta Maeda(Nagoya University), Takahiro Miwa(National research institute for earth science and disaster prevention), Takeshi Matsushima(Institute of Seismology and Volcanology, Faculty of Science, Kyushu University), Chairperson:Takeshi Tameguri(Sakurajima Volcano Research Center,Disaster Prevention Research Institute, Kyoto University), Keigo Yamamoto(Sakurajima Volcano Research Center, Disaster Prevention Research Institute, Kyoto University)

11:15 AM - 11:30 AM

[SVC31-09] Investigation of ground deformation due to a pressure source resembling the geometry of the low S-wave velocity region beneaththe Aira caldera, using a FEM model.

*Daisuke Miki1, Tomoki Tsutsui1, Masato Iguchi1 (1.Sakurajima Volcano Research Center, Disaster Prevention Research Institute, Kyoto University)

Keywords:Aira caldera, ground deformation, geometry of pressure source

We calculated the ground deformation due to a polyhedron pressure source resembling the geometry of the low S-wave velocity region beneath the Aira caldera, using a FEM model. This model is considered to be more compatible with recent seismological findings than conventional models such as the Mogi model. Calculated displacements are consistent with GPS and leveling survey observations as well as would be expected from the Mogi model. The area of crustal deformation is narrower when the pressure source has a vertical shape. On the other hand, the estimated magma supply to the Aira caldera, using the polyhedral pressure source model, is 10-20% larger than that assuming the Mogi model.