Frequency-dependent attenuation in eastern Kazakhstan and implications for seismic detection thresholds in the Soviet Union
Frequency-dependent attenuation in eastern Kazakhstan and implications for seismic detection thresholds in the Soviet Union
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DOI：
10.1785/bssa08006b2089
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发表时间：
1990-12
影响因子：
3
通讯作者：
T. Sereno
中科院分区：
文献类型：
--
作者：
T. Sereno
哈萨克斯坦东部核爆炸试验场附近的三个台站记录的区域地震相位的频率相关衰减是通过对距离在200至1300公里之间的21个震级在2.3至4.6之间的事件的频谱进行反演来估计的。Pn谱在1 ~ 10hz之间倒转，Lg谱在0.5 ~ 2.5 Hz之间倒转。进行这项研究的动机是，以前对苏联探测能力的估计是基于在其他地区（北美东部和斯堪的纳维亚半岛）记录的数据，因此具有很大的不确定性。最近在哈萨克斯坦东部记录的数据提供了一个很好的机会，可以将这些地点的区域波传播和噪声特征与以前探测能力模拟中假设的条件进行比较。发现哈萨克斯坦东部的衰减与斯堪的纳维亚半岛的衰减相差不大，但大于北美东部的衰减。这意味着，假设衰减与在北美东部观察到的衰减相似的检测阈值估计将低于假设衰减与在哈萨克斯坦东部或斯堪的纳维亚观察到的衰减相似的检测阈值估计。但是，不知道在哈萨克斯坦东部记录的数据在多大程度上代表了苏联其他地区的情况。
The frequency-dependent attenuation of regional seismic phases recorded by three stations near the nuclear explosion test site in eastern Kazakhstan is estimated by inverting spectra from 21 events with magnitudes between 2.3 and 4.6 at distances between 200 and 1300 km. The Pn spectra are inverted between 1 and 10 Hz, and the Lg spectra are inverted between 0.5 and 2.5 Hz. The motivation for this study is that previous estimates of detection capability in the Soviet Union are based on data recorded in other regions (eastern North America and Scandinavia) and therefore have large uncertainty. The data recently recorded in eastern Kazakhstan provide an excellent opportunity to compare regional wave propagation and noise characteristics at these sites to conditions assumed in previous detection capability simulations. It is found that attenuation in eastern Kazakhstan is not much different from attenuation in Scandinavia, but it is greater than attenuation in eastern North America. This implies that estimates of detection thresholds that assume attenuation like that observed in eastern North America will be lower than estimates of detection thresholds that assume attenuation like that observed in eastern Kazakhstan or Scandinavia. However, it is not known how well data recorded in eastern Kazakhstan represent conditions in other areas of the Soviet Union.