Basic research on the upgrade of coda-wave interferometry
| Project/Area Number |
16K05528
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Solid earth and planetary physics
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| Research Institution | Tohoku University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
江本 賢太郎 東北大学, 理学研究科, 助教 (80707597)
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| Project Period (FY) |
2016-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2018: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2017: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2016: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
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| Keywords | コーダ波干渉法 / 感度カーネル / 走時 / 地震波散乱 / 時間変化 / 干渉法 / 地震波速度 / 統計分布 / 地震波散乱特性 / デコリレーション / コーダ波 / 走時変化 / 地震波速度変化 / ベクトル化 / 散乱 |
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| Outline of Final Research Achievements |
Regarding studies on sensitivity kernels for coda-wave interferometry, we have tried to consider wave components. Based on the single-scattering approximation and a quasi-vector wave approximation, we have succeeded in formulating sensitivity kernels for locating regions of seismic velocity or scattering property changes in 2D and 3 D media. The single scattering approximation enabled us to derive analytical expressions for the sensitivity kernels. These results can be used to real data under the single scattering framework. As another application of coda-wave interferometry, we have also succeeded in formulating Rayleigh-wave coda decorrelation for closely located single forces. This result can be used to determine the separation distance of shallow nearby sources. In this way, we have upgraded the sensitivity kernels in coda-wave interferometry.
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| Academic Significance and Societal Importance of the Research Achievements |
コーダ波干渉法において，感度カーネルは地下構造が時間変化した場所を決める際に重要な役割を果たす．しかし，これまでのモデルでは，地震波の振動成分（上下，南北，東西方向）の情報をうまく取り込めていなかった．そこで本研究では，振動成分の情報を取り入れる（ベクトル波の定式化を行う）ことにより，コーダ波干渉法の感度カーネルの高度化を行った．1次散乱近似と準ベクトル波近似に基づき感度カーネルの解析表現の導出に成功した．この感度カーネルのベクトル化により，コーダ波干渉法において地震波の振動成分を有効利用する方法を明らかにし，今後地下構造の時間変化の場所を精度よく推定するための基礎を構築したことになる．
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Report
(5 results)
Research Products
(24 results)
