[SEM19-P03] Attempt at three-dimensional modelling of temporal change in resistivity structure beneath Aso volcano through the magmatic eruption in November, 2014
Keywords:Aso, volcano, electromagnetic, monitoring, resistivity
In order to interpret the ACTIVE data obtained before and after the magmatic eruption including topographic effects appropriately, we developed a three-dimensional forward code, by adopting a vector finite element method (FEM). In our forward modelling, the induction equation in terms of the vector potential, A, is solved with the gauge potential of phi=0 (Hano, 1991). We adopted unstructured tetrahedral mesh to represent arbitrary resistivity structure and complicated topography of volcanos. We demonstrated accuracy of our forward code in comparison to an analytical solution of Ward and Hohmann (1988), in a situation where a horizontal electric dipole is located just on one-dimensional layered structure. Currently, we are trying to apply an existing background conductivity structure obtained by AMT surveys to the background structure in our modelling, to investigate the cause of the temporal changes in the ACTIVE responses. In our presentation, we plan to show our results of forward modelling to interpret the temporal changes observed by ACTIVE system before and after the magmatic eruption in November, 2014.