S-Wave Velocity Structure of Upper Crust in Three Gorges Reservoir Region of the Yangtze River
Li Xiaoyong
Zhu Peimin
Zhou Qiang
Peng Songbai
Liu Jiangping
Liu Jiao
Abstract：In order to make a better understanding of the stability of the Three Gorges Reservoir region,the profile of S-wave velocity structure along Badong-Maoping-Tumen is presented using the ambient noise data observed at 10 stations from mobile broadband seismic array which is located at Three Gorges Reservoir region.All of available vertical component time series dur-ing April and May,201 1 have been cross-correlated to estimate the empirical Green functions.Group velocity dispersion curves were measured by applying multiple filtering technique.Using these dispersion curves,we obtain high resolution pure-path dis-persions at 0.5-10 s periods.The S-wave velocity structure,which was reconstructed by inverting the pure-path dispersions, reveals the velocity variations of upper crust at Three Gorges Reservoir region.Main conclusions are as follows.(1)The velocity variations in the study region have a close relationship with the geological structure and the velocity profile suggests an anticline unit which core area is Huangling block.(2)The relative fast velocity variations beneath Jiuwanxi and its surrounding areas may correspond to the geological structure and earthquake activity there.(3)The high velocity of the upper crust in Sandouping in-dicates that the reservoir dam of Three Gorges is located at a tectonic stable region.
Keywords：S-wave velocityThree Gorgesambient noisereservoir dam stabilityearthquake
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 1842-1850 )