| 講演要旨(和文) | | 地震発生深さのような地下深部の応力は、地震活動を知る上で非常に重要であるが、計測機器の制約や予算の限界で非常に難しいとされてきた。本研究では、地殻中を伝播してくる地震波散乱波が、地殻応力の情報を持っていると仮定し、地震波散乱波から応力の情報を得ることを目標とた。数値計算から地震波の減衰率と応力の大きさ、方向が関係性を持つことがわかった。また、実データにこの関係が成り立つか解析を行い、その関係性が見られた。 |
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| | 講演要旨(英文) | | Stress field deep under the ground, like seismogenic depth, is important to know seismic activity, state of oil reservoir, etc. However, we only know stress field near the earth surface using the current instruments and techniques. In this study, we focus on scattered seismic waves, which could have the whole information of the earth's crust where the seismic waves travel through, to obtain the stress field deep under the ground. Using the numerical simulation, the relationship between stress field and the seismic scattering has become clear. We found the magnitude of the stress has a proportional relationship with attenuation ratio of the scattering. The relationship is confirmed by using sets of real field data. |
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