| 講演要旨(和文) | | 本研究は，福島県の10地点において広帯域リニアアレイ観測を実施し，地震波干渉法解析により水平動を用いて相互相関関数の算定と群速度の算定を行った．観測された常時微動水平動記録に対しアレイ観測点間の相互相関関数を算出した結果，Radial成分とTransverse成分の双方で特徴的な位相が伝播する様子が確認できた．重合した相互相関関数にマルチプルフィルタ解析を適用し群速度分散曲線と周期ごとのSN比を推定した．RRとTTの群速度分散曲線を比較した結果，周期5秒以下ではTTの群速度が遅いが，周期5秒以上でTTの群速度が速いことが分かった．そして，RRとZZは群速度がほぼ同じ値だった．Nishidaモデルから期待される群速度理論分散曲線と観測とを比較した結果，観測値のほうが群速度が低いことがわかった． |
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| | 講演要旨(英文) | | The purpose of this study is to conducted a broadband linear array observation with 10 sites in Fukushima Prefecture in order to estimate deep crustal structures down to the plate boundary based on the seismic interferometry analysis. In this study radial and transverse cross-correlation functions were calculated from observed horizontal records of microtremors and group velocities were calculated from the estimated cross-correlation functions. Both of the radial cross-correlation functions and the transverse ones showed wave-propagation characteristics. SN ratios and group velocities were estimated as a function of periods by applying multiple filter analysis to stacked cross-correlation functions. From the comparison between the group velocity of RR and one of TT, the velocity of TT was larger than one of RR at periods of more than 5 s. From a comparison between the observed group velocities and calculated ones by Nishida's Vs model, observed group velocities were smaller than calculated ones. |
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