通过地震横波获取地壳深浅部应力简介

A brief overview of using seismic S-waves to determine deep and shallow crustal stress

地震是脆性地壳中断层应力积累超过破裂极限强度的直接结果。因此,研究地壳不同深度的应力积累是地震预报的可能途径之一。在各种地球物理观测数据中,地震各向异性介质中的地震横波分裂参数携带了不同深度岩层中应力及其变化的完整信息。这些参数中,快横波偏振方向的观测已经取得了大量的成果。但是,过去40年来,快-慢横波到时差的观测数据过于离散,制约了利用地震横波来了解深浅部岩层中应力大小的观测和研究。对此,本文简要介绍了相关研究存在的难点和解决方法、以及专门的地震波偏振矢量分离(SPVS)观测软件,有望实现对地震孕育、发生和发展过程中应力及其变化的监测。

Earthquakes result from stress accumulation exceeding the fracture limit strength in the brittle crustal layers.Consequently,investigating stress accumulation at different depths within the Earth’s crust represents a potential avenue for earthquake prediction.Among various geophysical observation datasets,seismic shear wave splitting parameters within seismically anisotropic media encapsulate comprehensive information on stress and its variations within different depth layers.Notably,substantial progress has been made in the observation of fast shear wave polarization directions.However,over the past four decades,observations of the time delays between fast and slow shear waves have been excessively sparse,constraining the observational and investigative endeavors aimed at understanding stress magnitudes in deep and shallow rock layers using seismic shear waves.To address this issue,this paper succinctly outlines the challenges associated with relevant research,proposes corresponding solutions and introduces the Seismic Polarization-Vector Separation(SPVS)observation software with the potential to facilitate monitoring stress and its variations during the seismic nucleation,occurrence,and processes.