Love Wave Tomography Of Fujian From Ambient Seismic Noise

Fujian Province is located in the southeastern edge of the Eurasian plate.The interaction of Eurasian plate, the Pacific plate and the Indian platemakes the geological structure of this area is complex. Geological structurebelongs to Wuyi-Yunkai-Taiwan tectonic units. Fujian province is runthrough by the Cathaysian block in the northwest and the southeast coastalmagmatic arc in the southeast. Fujian Province is located in the northern partof the southeast coastal seismic area, including Quanzhou, Shaowu, Heyuanseismic zone. As the Pacific plate subducts to the Eurasian continent, a seriesof faults staggered distributes in Fujian Province, including:Zhenghe-Haifeng fault, Shaowu-Heyuan fault, Changle-Zhao’an fault,Shanghang-Zhao’an fault, Jiulong River fault, Shaxian-Nanri island fault,Yongan-Jinjiang fault, Min Jiang fault. Fujian area is affected by theearthquake severely, there is a8.0earthquake in Quanzhou in history.In this paper we use ambient noise tomography method, based on thebackground noise recoding recorded by the digital broadband seismicnetwork of Fujian province and its neighboring provinces. The main researchobjective of this paper is Love surface wave group velocity tomography indifferent periods and transverse wave velocity structure underground. Wealso compare the result to the landform of the Fujian region, in order toprovide a reference of geological studies of shallow crustal.In this article we extract empirical Green’s function of Love surface waveusing the cross-correlation calculation, using the multiple filter method（MFT） extract Love surface wave’s group velocity dispersion curves, andobtain high-resolution group velocity distribution of Love surface waveusing tomography method in different periods. Different period’s Lovesurface has different most sensitive depth. Short-period group velocitydistribution maps is basically fitted with mountains and basin distribution ofFujian. Distribution map of Love surface wave group velocity show high-velocity in mountains and low-velocity in basins.In this paper we invert transverse wave velocity structure underground ofFujian Province using Love surface wave group velocity dispersion curvesand generate a series of shear wave velocity distribution maps of differentdepth. By considered the shear wave velocity distribution map of differentdepth, the results show that Fujian region’s crust is divided into the uppercrust and lower crust. The also show that the thickness of sedimentary layerfo the two basins, Fuzhou basin and Zhangzhou basin are about10km.