A Next Generation VS30 Map for California Based on Geology and Topography
A Next Generation VS30 Map for California Based on Geology and Topography
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DOI：
10.1785/0120150105
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发表时间：
2015-12
影响因子：
3
通讯作者：
C. Wills;C. Gutierrez;F. G. Perez;D. Branum
中科院分区：
文献类型：
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作者：
C. Wills;C. Gutierrez;F. G. Perez;D. Branum
摘要 地质单元和剪切波速度之间的相关性构成了过去 15 年开发的一系列地图的基础，用于估计上部 30 m 的时间平均剪切波速度 ( V S 30 )。遗嘱等人。 (2000) 加利福尼亚州的场地条件图被发现与地震放大相关 (Field, 2000)，并被采用作为地震振动估计的许多应用的标准描述（例如 ShakeMap）。 Wills 和 Clahan (2006) 修改了该地图以显示简化的地质单元和相应的 V S 30 值。这张地图的准备提出了一些关于如何最好地区分较年轻冲积层中的单元的问题。 Wills 和 Gutierrez (2011) 发现，基于表面坡度的简单系统可用于将较年轻的冲积层细分为具有不同 V S 30 范围的三类。由坡度定义的类别在 V S 30 中具有与先前定义的类别大致相同的变异性，但类别总数减少了，并且该系统可以轻松应用于其他构造活动区域。我们现在应用了 Wills 和 Gutierrez (2011) 的系统，使用最详细的可用地质图创建了一张新的加利福尼亚州地图。使用更详细的地质图（加州大部分地区的比例尺从 1:250,000 到 1:24,000）可以更详细、更准确地描述地表地质，并且我们预计，可以更详细、更准确地描述由于近地表材料而产生的地震放大。在线资料：比例尺为 1:1,500,000 的加利福尼亚州场地状况地图，以及 ArcGIS 格式。
Abstract Correlations between geologic units and shear-wave velocity form the basis of a series of maps developed over the past 15 years to estimate the time-averaged shear-wave velocity in the upper 30 m ( V S 30 ). The Wills et al. (2000) site-condition map for California was found to correlate with seismic amplification (Field, 2000) and was adopted as a standard depiction for many applications of seismic shaking estimates (ShakeMap, for example). Wills and Clahan (2006) modified that map to show simplified geologic units and corresponding V S 30 values. Preparation of this map raised a number of questions on how best to distinguish units within younger alluvium. Wills and Gutierrez (2011) found that a simple system based on surface slope could be used to subdivide the younger alluvium into three classes that have distinct V S 30 ranges. The classes defined by slope have approximately the same variability in V S 30 as the previously defined classes, but the total number of classes is reduced and the system can be easily applied to other tectonically active areas. We have now applied the system of Wills and Gutierrez (2011) to create a new map of California using the most detailed available geologic maps. Use of more detailed geologic maps, from 1:250,000 scale to 1:24,000 for much of California, results in a much more detailed and accurate depiction of the surficial geology and, we anticipate, a more detailed and accurate depiction of seismic amplification due to the near-surface materials. Online Material: Site-condition map of California at a scale of 1:1,500,000, as well as in ArcGIS formats.