有分布式声学传感的地震焦点机制
Jiaxuan Li1, Weiqiang Zhu2, Ettore Biondi2
1Seismological Laboratory, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA. jxli@caltech.edu.
Nature communications
|July 13, 2023
概括
这项研究引入了一种新的方法,使用分布式声学传感 (DAS) 数据来确定地震焦点机制. 将DAS与传统的地震计相结合,可以提高小地震断层方向的准确性.
科学领域:
- 地质物理学 地质物理学
- 地震学 地震学
- 地震科学 地震科学 地震科学
背景情况:
- 地震焦点机制揭示了地下断层和压力.
- 对于小地震 (强度<3.5) 的传统方法依赖于地震仪的极性,但受到有限的亚齐图斯覆盖的困扰.
- 分布式声学传感 (DAS) 提供密集的空间采样和远距离传感,有可能改善亚齐木斯通覆盖范围.
研究的目的:
- 开发和验证一种数据驱动的方法,用于测量地震焦点机制反转的DAS数据的P波极性.
- 评估将DAS衍生的极性与传统地震网络数据集成的有效性.
- 为了提高地震焦点平面方向的准确性和减少不确定性.
主要方法:
- 一种新的数据驱动方法来测量DAS阵列上的P波极性,使用地震对之间的交叉相关性.
- 根据区域地震网络目录验证推断的DAS极性.
- 联合焦点机制反转,结合传统的地震和DAS极性数据.
主要成果:
- 成功地从两个加利福尼亚部署的DAS数据中推断出P波极性.
- 证明了常规和DAS极性的联合反转可以提高焦平面定向的准确性.
- 在将DAS数据纳入时,显示了焦平面方向的不确定性减少.
结论:
- 开发的方法有效地从DAS中提取P波极性,克服单元感应和低信号噪声比的挑战.
- 将DAS与传统的地震网络集成,显著提高了地震焦点机制研究的分辨率和可靠性.
- 对于推进高分辨率的地震源机制调查,DAS技术具有很大的前景.
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