Details of the Abstract
| Title of paper | Attempt to estimate the underground resistivity structure of Kozushima using the electric field variation caused by the 2011 Tohoku tsunami |
| List of authors | Takebayashi, T., Minami, T. |
| Affiliation(s) | Graduate School of Science, Kobe University, Japan, Graduate School of Science, Kobe University, Japan |
| Summary | Through the dynamo effect, tsunami propagation generates observable variations in the electric field as well as the magnetic field. On Kozushima, one of the Izu Islands in Japan, electric field variations were observed during the tsunami caused by the 2011 Tohoku earthquake, corresponding to changes in nearby tidal record data. A previous study suggests that tsunami-generated electric field variations observed on islands depend on underground resistivity. In this study, we attempted to estimate the resistivity structure of Kozushima that explains the electric field variations observed during the tsunami event. Three-dimensional simulations of tsunami electric fields were performed using structures with uniform resistivity and a structure with an L-shaped low-resistivity zone. The observed electric field variation was significant in the east-west direction. In the simulations, variation in the north-south direction was notable with the uniform structures, whereas variations in the east-west and north-south directions were comparable with the structure featuring the L-shaped low-resistivity zone. These results imply that the resistivity structure of Kozushima possibly exhibits a complex pattern that amplifies the electric field variations in the east-west direction. |
| Session Keyword | 6.0 Marine and airbone EM |
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