[SSS15-P02] Gravity survey and subsurface structure across the Aomoriwan-Seigan Fault Zone, Northeast Japan(part 2; estimation of the subsurface structure using the density of rock samples)
Keywords:Gravity survey, Bouguer gravity anomaly, Rock density measuring, Aomoriwan-Seigan Fault Zone, Seismic reflection survey, CSAMT survey
In the previous our presentation in the 2018 JpGU (Okada et al., 2018), we use the Talwani method (Talwani et al., 1959) to calculated the Bouguer gravity anomaly, in which the subsurface density structure is determined from the interpretation of the seismic and CSAMT surveys (Kagohara et al., 2017; Sakashita et al., 2017). In a part of the western part of the profile, there were some discrepancies between calculated and observed gravity anomalies. And it was also difficult to estimate the density of each layers. To resolve these problems, we conducted additional field survey and obtained several rock samplings from outcrops around the survey line, which we measured the density of samplings based on the method of Murata et al. eds. (1991). The discrepancies between calculated and observed gravity anomaly were improved by take into the layer densities from samplings.
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