Estimating Subsurface Shear Velocity with Radial to Vertical Ratio of Local P Waves
Estimating Subsurface Shear Velocity with Radial to Vertical Ratio of Local P Waves
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DOI：
10.1785/0220130128
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发表时间：
2014
影响因子：
3.3
通讯作者：
S. Ni;Zhiwei Li;P. Somerville
中科院分区：
文献类型：
--
作者：
S. Ni;Zhiwei Li;P. Somerville
在线资料：r/z比法求V S代码；地震图解。与美国西部地震活动高、地震台网密集的地区相比，美国中部和东部(CEU)覆盖着稀疏的地震台网。CEU中相对较低的地震活动也导致了来自当地地震的波形数据的有限数据集，阻碍了CEU中可靠的地面运动预测方程的发展。随着地球望远镜可移动阵列(USArray)计划从2009年开始在CEU中安装约1000个宽带和短周期站点，这种情况已经改变，并将很快全面覆盖CEU。如此多的观测站为美国的地面运动研究提供了丰富的数据集。此外，越来越多的先进国家地震系统(ANSS)宽带站具有高采样率，大大增加了波形数据。在将波形数据用于地面运动研究之前，需要获得每个地震台的场地响应。例如，Boore(2003)和Atkinson and Boore(2006)发现，北美东部的地面运动模型需要考虑场地放大，特别是对于高频。场地响应受地下剪切速度剖面的控制，顶部十米到几百米的速度结构尤为重要(Wald和Mori，2000；Boore，2006)。因此，场地响应模拟的一个重要部分是确定地下速度结构。Boore(2006)对确定地下速度结构的方法进行了详细的回顾。从理论上讲，井眼测井等侵入性方法提供了最准确的速度结构测量，但其成本限制了其在现场响应研究中的广泛应用。非侵入性地球物理勘探方法在确定浅层速度结构中应用较多，这些方法包括面波频谱分析、多道…
Online Material: Code for computing V S by the r/z ratio method; seismogram plots. In contrast to the western United States where seismicity is high and seismic networks are dense, the central and eastern United States (CEUS) is covered with sparse seismic networks. The relatively low seismicity in the CEUS has also led to a limited dataset of waveform data from local earthquakes, hindering the development of reliable ground‐motion prediction equations in the CEUS. This situation has been changing with the Earthscope Transportable Array (USArray) program that started installing about 1000 broadband and short‐period stations in the CEUS starting in 2009, and will fully cover the CEUS soon. Such large numbers of stations provide a rich dataset for ground‐motion studies in the United States. Also, the increasing number of Advanced National Seismic System (ANSS) broadband stations with high‐sampling rate substantially augments the waveform data. Site responses at each seismic station need to be obtained before the waveform data can be used for ground‐motion studies. For example, Boore (2003) and Atkinson and Boore (2006) find that site amplification needs to be taken into account for ground‐motion modeling in eastern North America, especially for high frequencies. Site response is controlled by the subsurface shear‐velocity profile, and the velocity structure of the top ten to hundreds of meters is particularly important (Wald and Mori, 2000; Boore, 2006). Therefore an essential part of site‐response modeling is determining subsurface velocity structure. A detailed review of methods for determining subsurface velocity structure was made by Boore (2006). Theoretically, invasive methods such as borehole logging provide the most accurate measurement of velocity structure, but their cost prohibits extensive application in site‐response studies. Noninvasive geophysical exploration methods are more often used in determining shallow velocity structure, and these include spectral analysis of surface waves (SASW), multichannel …