Global teleseismic earthquake relocation with improved travel times and procedures for depth determination
Global teleseismic earthquake relocation with improved travel times and procedures for depth determination
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DOI：
10.1785/bssa0880030722
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发表时间：
1998-06
影响因子：
3
通讯作者：
E. Engdahl;R. Hilst;R. Buland
中科院分区：
文献类型：
--
作者：
E. Engdahl;R. Hilst;R. Buland
我们重新定位了1964年至1995年期间发生的近100，000起事件，这些事件在地震学上受到国际地震中心（ISC）和美国地质调查局国家地震信息中心（NEIC）报告的到达时间数据的约束。除了使用区域和地震P和S相位外，还使用PKiKP、PKPdf的到达时间以及重新定位过程中的地震深度相位pP、P2P和sP，从而显著改善了震源确定。一个全球性的概率模型开发的后到达的相位被用来独立地识别的深度相位。的搬迁相比，在ISC和NEIC目录和其他来源的震源报告。我们的震中与ISC和NEIC估计的差异一般是小的，区域系统的综合影响的观测站网络和板块的几何形状区域，在上地幔旅行时间之间的差异使用的参考地球模型，并使用较晚到达的阶段。震源深度大大提高了大多数其他独立的估计，演示（例如）如何区域结构，如下行板可以严重偏差深度估计时，只有区域和双折射P到达用于确定震源。新的数据库，这是完整的约Mw 5.2，包括所有事件的时刻张量解决方案是可用的，立即应用到高分辨率定义的Wadati-Benioff区（WBZ）全球，区域和全球层析成像，以及其他研究地球结构。
We relocate nearly 100,000 events that occurred during the period 1964 to 1995 and are well-constrained teleseismically by arrival-time data reported to the International Seismological Centre (ISC) and to the U.S. Geological Survey's National Earthquake Information Center (NEIC). Hypocenter determination is significantly improved by using, in addition to regional and teleseismic P and S phases, the arrival times of PKiKP, PKPdf, and the teleseismic depth phases pP, pwP, and sP in the relocation procedure. A global probability model developed for later-arriving phases is used to independently identify the depth phases. The relocations are compared to hypocenters reported in the ISC and NEIC catalogs and by other sources. Differences in our epicenters with respect to ISC and NEIC estimates are generally small and regionally systematic due to the combined effects of the observing station network and plate geometry regionally, differences in upper mantle travel times between the reference earth models used, and the use of later-arriving phases. Focal depths are improved substantially over most other independent estimates, demonstrating (for example) how regional structures such as downgoing slabs can severely bias depth estimation when only regional and teleseismic P arrivals are used to determine the hypocenter. The new data base, which is complete to about Mw 5.2 and includes all events for which moment-tensor solutions are available, has immediate application to high-resolution definition of Wadati-Benioff Zones (WBZs) worldwide, regional and global tomographic imaging, and other studies of earth structure.