InSAR同震形变场及其在震源参数确定中的应用研究进展

合成孔径雷达干涉测量(InSAR)技术是20世纪70年代发展起来的一种空间大地测量技术,具有全天时、全天候、高精度、广域覆盖的优势,自20世纪90年代以来在地震地壳形变监测研究领域得到了广泛应用,对地震发生机理研究具有重要意义。尤其是InSAR技术观测的同震地壳变形结果可以为分析发震断层几何学特征和动力学机制提供重要约束。随着InSAR技术的发展,如何获取可靠、多维的同震形变场,构建更加真实的正反演模型,是利用InSAR技术研究地震震源参数的关键。首先,综述了利用InSAR技术获取同震形变场的研究现状,总结了InSAR技术获取同震形变场的优缺点、InSAR技术获取三维同震形变的现状; 接着,回顾了地震震源参数正反演模型及方法的研究历程,包括从简单的弹性半空间位错模型到接近真实地球介质的数值模型,分析了不同反演方法和先验约束对结果的影响; 最后,从同震形变场分离、自动化InSAR数据处理与震源参数反演等方面进行了展望。综上所述,InSAR技术获取的同震形变场具有大范围、高精度的优势; 随着精细地壳介质参数的逐步确定,联合地震学技术方法,InSAR技术可以反演确定比较准确的地震震源参数。

Review on InSAR-derived Coseismic Deformation and the Determination of Earthquake Source Parameters

Interferometry synthetic aperture radar(InSAR), which is a spatial geodetic technique developed at 1970s, has the advantages of all day and night, all weather, high-precision and wide area coverage. Owing to these advantages, InSAR has been widely used in the area of coseismic deformation detection from 1990s, and is helpful for studying the mechanism of earthquake significantly. In particular, the coseismic crustal deformation observed by InSAR can be used as an important constraint to analyze the geometric characteristics and dynamic mechanism of seismogenic faults. With the continuous improvement of InSAR, how to obtain the coseismic deformation field more reliably and how to build a more real and efficient forward and inverse model are the keys to use InSAR to study earthquakes. The advantages and disadvantages of detecting coseismic deformation using InSAR, and overview of 3D coseismic deformation using InSAR, were firstly reviewed. Then, an overview of inversion for source parameters on a seismogenic fault was analyzed comprehensively, including the elastic half-space fault model, numerical model with anisotropic medium, inversion methods, and a priori constraints. Finally, the separation of deformation caused by several earthquakes, and automatic InSAR data processing and seismogenic fault parameters inversion were prospected. It is concluded that the InSAR-derived coseismic deformation field has the advantage of large-area and high-precision. InSAR can achieve precise earthquake source parameters combining seismology methods.