[M-GI28] データ駆動地球惑星科学

[MGI28-P01] ベイズ推論を用いた地震波速度と電気比抵抗からの岩相・地殻流体推定

*桑谷 立¹、永田 賢二²、酒井 俊元³、岩森 光⁴ (1.国立研究開発法人　海洋研究開発機構、2.国立研究開発法人　物質・材料研究開発機構、3.有限会社　チェスターフォード、4.東京大学地震研究所)

キーワード：地殻流体、ベイズ推論

It is important to convert geophysical observations of the earth's interior into geological information, such as rock type and geofluid amounts. In this study, we develop a Bayesian inversion method that estimates lithology, geofluid types, amounts, and related parameters from seismic-velocity and electric-conductivity data. The proposed method utilizes a marginalization technique to first select the lithology and geofluid types, then quantify the geofluid parameter values. Through artificial data tests, we demonstrate that our method can evaluate the possibility of various combinations of lithology and geofluid types from over a hundred candidate sets, providing approximate estimations for other unknown parameters. In our presentation, we will introduce the methodology and results, as detailed in the recently published paper by Kuwatani et al. (2023, JGR: Solid Earth), and discuss the challenges and potential applications.