On the Amplitude Characteristics of Microtremor (Part 1)
On the Amplitude Characteristics of Microtremor (Part 1)
复制标题
论微震的振幅特性（一）
DOI：
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发表时间：
1970
期刊：
影响因子：
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通讯作者：
T. Igarashi
中科院分区：
文献类型：
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作者：
M. Nogoshi;T. Igarashi
本文讨论了作为微震基本特征的振幅特征。试验田是北海道的函馆市。将地脉动的随机物理现象视为平稳随机过程。为了表示地脉动的幅值特征，计算了功率谱密度函数。微震幅值的统计检验采用x~2检验。地下结构的理论振幅特征是根据多次反射理论得出的最小群速度频率和M1波的振幅比。并与微震功率谱密度函数的优势频率进行了比较。从仅考虑地震动幅值特征的优势频率的角度出发，从这些比较中可以得出这样的结论：地震动的水平分量可以看作S波结构的幅值比的幅值特征或地基与基底交界处的Love波的基本振型。然而，微波垂直分量的幅值特征与p波结构的幅值比不一致，与瑞雷波基模的幅值特征是否一致。并将爆炸地震观测的波形频谱与多次反射理论的振幅特性、面波的最小群速度和微震的功率谱进行了比较。
The amplitude characteristics as the fundamental natures of microtremors was discussed at the present paper. The experimental field is Hakodate City in Hokkaido. The random physical phenomena of microtremors were treated as the stationary random process. In order to express the amplitude characteristics of microtremors, power spectral density functions were therefore computed. The statistical check of the amplitudes microtremors was used by means of x2-test. Theoretical amplitude characteristics from the underground structure is the frequency of the minimum group velocity of Loand M1-wave and the amplitude ratio by the theory of multiple reflection. They were compared with the predominant frequencies of power spectral density functions of microtremors. From the point of view to remark only the predominant frequency at the amplitude characteristics of microtremor, we may conclude from these comparisons that the horizontal component of microtremors can be treated as the amplitude characteristics of the amplitude ratio from S-wave structure or the fundamental mode of Love wave at the places where the boundary of the subsoil and basement is district. However, the amplitude characteristics of the vertical component of microtermor never agrees with the amplitude ratio from Pwave structure, and it agrees or not with the amplitude characteristics of the fundamental mode of Rayleigh wave. Furthermore, the spectra of waveform by explosion seismic observation was compared with the amplitude characteristics from the theory of multiple reflection, the minimum group velocity of surface wave and the power spectra of microtremor.