Simultaneous waveform inversion for three‐dimensional Earth structure and earthquake source parameters considering a wide range of modal coupling
Simultaneous waveform inversion for three‐dimensional Earth structure and earthquake source parameters considering a wide range of modal coupling
复制标题
考虑大范围模态耦合的三维地球结构和震源参数同步波形反演
DOI：
10.1046/j.1365-246x.2000.00168.x
复制
发表时间：
2000
影响因子：
2.8
通讯作者：
R. Geller
中科院分区：
文献类型：
--
作者：
T. Hara;R. Geller
总结
我们进行迭代反演的长周期地震波形数据，同时确定三维结构的上，最上层的下地幔和震源参数。我们使用Geller & Hara（1993）和Hara（1997）的方法对观测数据进行直接反演，因此不使用诸如“分裂函数”之类的中间参数。我们用直接解法（DSM）分析了178-185、282-299和347-376 s周期段的资料，计算了合成地震图及其偏导数。在这些计算中考虑了各种模态耦合。我们进行的数值实验表明，忽略环-球耦合可以显着偏置的周期带282-299秒的3-D地球结构的估计，注意，以前的研究，这一带一般没有考虑这样的耦合。对周期带347-376 s的数值实验表明，我们的反演方法比以往的方法能提取更多的关于周期带347-376 s的奇角序结构的信息.
Summary
We perform iterative inversion of long-period seismic waveform data to determine simultaneously the 3-D structure of the upper and uppermost lower mantle and earthquake source parameters. We perform direct inversion of the observed data using the methods of Geller & Hara (1993) and Hara (1997), thus intermediate parameters such as ‘splitting functions’ are not used. We analyse data in the period bands 178-185, 282-299 and 347-376 s using the Direct Solution Method (DSM) to compute synthetic seismograms and their partial derivatives. A wide range of modal coupling is considered in these computations. We conduct numerical experiments that show that neglecting toroidal-spheroidal coupling can significantly bias estimates of 3-D Earth structure for the period band 282-299 s; note that previous studies for this band generally did not consider such coupling. A numerical experiment for the period band 347-376 s suggests that our inversion approach can extract more information on odd angular order structure for the period band 347-376 s than previous techniques.