Coda wave imaging of the Long Valley Caldera using a spatial stacking technique
Coda wave imaging of the Long Valley Caldera using a spatial stacking technique
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使用空间叠加技术对长谷火山口进行尾波成像
DOI：
10.1029/97gl01468
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发表时间：
1997
影响因子：
5.2
通讯作者：
John Mc Closkey
中科院分区：
文献类型：
--
作者：
Kathryn B. O'Doherty;C. Bean;John Mc Closkey
对加州东部长谷破火山口的大量地质和地震学研究表明，它目前是一个活跃的岩浆系统。传统上，利用当地和区域地震数据的层析成像测量是根据“直接”到达的原则进行的。本文介绍了一种用于对S波衰减结构进行成像的技术的结果。我们从近17，000个垂直分量地震记录中测量了S波尾波的衰减值。一个更稳定的估计Q确定尾波是不太敏感的本地路径效应比直接波，因为它们采样的体积。我们发现，从空间叠加产生的断层图像显示出高衰减异常（Qs <$125）内的破火山口为中心相比，Qs <$220外的破火山口。
Numerous geological and seismological studies of the Long Valley caldera, eastern California, suggest that it is at present an active magmatic system. Tomographic measurements utilising local and regional earthquake data have traditionally been made on the principle ‘direct' arrivals. This paper presents the results from a technique developed to image the S‐wave attenuation structure. We measure the attenuation value of the S‐wave coda from almost 17,000 vertical‐component seismograms. A more stable estimate of Q is determined from coda waves which are less sensitive to local path effects than direct waves as they sample a volume. We find that the resultant tomograms produced from spatial stacking show a high attenuation anomaly (Qs ∼ 125) centred within the caldera compared with Qs ∼ 220 outside the caldera.