| 講演要旨(和文) | | 地下の速度不連続に関する情報を得るための簡便法として，レーリー波位相速度の分散データを用いて微動の水平−鉛直動パワー比（H/Vスペクトル）の周波数を深さに変換してHV比のピークまたは谷を速度不連続と解釈するアプローチを提案する．微動の波動場を複数モードのレーリー波とラブ波が卓越すると仮定した理論計算により本手法の適用性が示された． |
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| | 講演要旨(英文) | | We propose a simple method for acquiring information on subsurface S-wave velocity discontinuities. In this approach, each frequency in the horizontal-to-vertical spectral ratio (H/V spectrum) of microtremors is converted into depth by means of dispersion data on the phase velocities of Rayleigh waves. Herein, this is referred to as the depth conversion of the H/V spectrum. The method involves the interpretation of either the peaks or troughs of the H/V spectrum as velocity discontinuities at certain depths. We theoretically calculated the depth conversions of H/V spectra for various types of velocity structure by assuming that multiple modes of Rayleigh and Love waves dominate a microtremor wavefield. A comparison between the given velocity structure and the theoretical H/V depth distribution indicated the applicability of the proposed method. |
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