| 講演要旨(和文) | | 地震発生時，平野部では堆積層の影響を受けて長周期の表面波が生成・伝播する．笠松・酒井(2013年春季学術講演会)は，関東平野で観測された2011年富士山付近の地震(Mj6.4)による周期約7〜8秒のラブ波に注目し，伝播特性の再現性という観点から既往の３次元堆積層構造モデルの妥当性・課題点を把握した．本検討はそのラブ波再現性を向上させるため，ラブ波を用いて２次元堆積層構造を推定する方法を考えた．この方法の有効性および推定精度を把握するため，上記地震の地震動シミュレーション結果に適用し，正解となる構造を既知とした数値実験を行った．堆積層構造の３次元性を２次元で近似した違いによりラブ波生成と係わりが深い傾斜が急な場所である程度の違いは認められたが，推定結果の堆積層構造と正解の構造は全体的によく整合し，この方法により対象断面の分布を概ね把握できることを確かめた． |
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| | 講演要旨(英文) | | When the earthquake occurred, surface wave were generated and propagated influenced by sedimentary layers. I focused on Love wave (T=7-8s) in Kanto basin during the 2011 Mt. Fuji Region earthquake (Mj6.4), and tried to understand the validity and problems of the past structure model based on the reproducibility of the propagation characteristic (Spring Meeting, 2013). To improve the reproducibility, I thought out a new waveform inversion method for estimating 2D sedimentary layers using Love wave. To investigate the effectiveness and accuracy of this method, I applied to the result of the 3D ground motion simulation of the 2011 Mt.Fuji Region Earthquake. As a result of this numerical experiment, the conspicuous difference was found around a steep slope by the difference which approximated the 3D sedimentary layers structure by 2D. But, on the whole, the answered and the estimated 2D sedimentary layers were adjusted well, and I found that it's possible to grasp the 2D characteristic distribution using this method. |
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