SUMMARY

The horizontal to vertical spectral ratio (HVSR) of seismic ambient noise has been proven to be a fast and efficient method for characterizing the 1-D resonance frequency of the local subsurface in a practical framework. Over the last decades, theories have been developed in order to extend the exploitation of HVSR beside the frequency of its first peak, notably the diffuse field assumption (DFA) which links the HVSR to the Green’s function of the local medium assuming the diffuseness of the seismic ambient noise wavefield. However, the underlying assumption of the seismic ambient noise being a diffuse, equipartitioned field may not be satisfied under certain circumstances. In order to exploit the contribution of scattering in forging diffuse wave fields, we leverage the advantages of coda waves and present a novel procedure for computing the HVSR, using the coda part of ambient noise correlations. We applied this technique to data gathered at the plio-quaternary sedimentary basin of Argostoli, Greece. Results on this data set show the potential of the method to improve the temporal stability of the HVSR measurements compared to the classical computation, and the fit with the theoretical HVSR curve derived from the DFA theory. These results suggest that this procedure could help in extracting physical information from the HVSR and thus could lead to an extended use of these measurements to characterize the mechanical properties of the medium.

中文翻译：

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关于使用地震噪声自相关的尾迹来计算H / V谱比

概要

地震环境噪声的水平与垂直频谱之比（HVSR）已被证明是在实际框架中表征局部地下一维共振频率的快速有效方法。在过去的几十年中，为了将HVSR的利用扩展到其第一个峰值的频率之外，已经开发了一些理论，特别是将HVSR与本地介质的格林函数联系起来的扩散场假设（DFA），假设地震环境噪声波场。但是，在某些情况下可能无法满足地震环境噪声为弥散，等分场的基本假设。为了利用散射在锻造扩散波场中的作用，我们利用了尾波的优势，并提出了一种计算HVSR的新颖方法，使用环境噪声相关性的尾声部分。我们将此技术应用于在希腊阿尔戈斯托利（Argostoli）的脊灰-第四纪沉积盆地收集的数据。与经典计算相比，该数据集上的结果表明该方法具有改善HVSR测量的时间稳定性的潜力，并且与从DFA理论导出的理论HVSR曲线吻合。这些结果表明，该程序可以帮助从HVSR中提取物理信息，因此可以导致这些测量方法的广泛应用来表征介质的机械性能。与经典计算相比，该数据集上的结果表明该方法具有改善HVSR测量的时间稳定性的潜力，并且与从DFA理论推导出的理论HVSR曲线吻合。这些结果表明，该程序可以帮助从HVSR中提取物理信息，因此可以导致这些测量方法的广泛应用来表征介质的机械性能。与经典计算相比，该数据集上的结果表明该方法具有改善HVSR测量的时间稳定性的潜力，并且与从DFA理论推导出的理论HVSR曲线吻合。这些结果表明，该程序可以帮助从HVSR中提取物理信息，因此可以导致这些测量方法的广泛应用来表征介质的机械性能。