Surface Wave Group Velocity Tomography Imaging from Ambient Noise for Fujian Province and Its Adjacent Areas

作者：ZHANG Lina,LUO Yan,CHEN Zhiyong,XIE Zhizhao,ZHOU Lanjie,ZENG Xiangfang

摘要：Two-month continuous waveforms of 108 broadband seismic stations in Fujian Province and its adjacent areas are used to compute noise cross-correlation function (NCF). The signal quality of NCF is improved via the application of time-frequency phase weighted stacking. The Rayleigh and Love waves group velocities between 1s-20s are measured on the symmetrical component of the NCF with the multiple filter method. More than 5,000 Rayleigh wave dispersion curves and about 4,000 Love wave dispersion curves are obtained and used to invert for group velocity maps. This data set provides about 50km resolution that is demonstrated with checkerboard tests. Considering the off great circle effect in inhomogeneous medium, the ray path is traced based on the travel time field computed with a finite difference method. The inverted group velocity maps show good correlation with the geological features in the upper and middle crust. The Fuzhou basin and Zhangzhou basin showed low velocity on the short period group velocity maps. On the long period group velocity maps, the low velocity anomaly in the high heat flow region near Zhangzhou and clear velocity contrast across the Zhenghe-Dapu faults, which suggests that the Zhenghe-Dapu fault might be a deep fault.

发文机构：Xiamen Seismic Survey Research Center Institute of Earthquake Forecasting Fujian Earthquake Agency State Key Laboratory of Geodesy and Earth's Dynamics

关键词：FujianAMBIENTnoiseSurfaceWAVEGROUPVELOCITYTOMOGRAPHYIMAGING

分类号： P[天文地球]