%0 Journal Article %A LUO Jia-hong %A MA Wen-tao %T A PRELIMINARY STUDY ON UPPER CRUSTAL VELOCITY STRUCTURE IN THE THREE GORGES RESERVOIR AREA %D 2016 %R 10.3969/j.issn.0253-4967.2016.02.008 %J SEISMOLOGY AND GEOLOGY %P 329-341 %V 38 %N 2 %X

In this paper, using the double difference tomography method, the P wave and S wave velocity structures of the earth's crust beneath the Three Gorges Reservoir are inversed based on the high-resolution seismic data of seismological stations recorded from March 2009 to December 2010. According to the research results, the P wave and S wave crust velocity zones in the Three Gorges Reservoir area show a high VP value area and a VS value area with value low in the lower part and high in the upper part, distributing respectively at both sides of Shennongxi River to western Xietan in the north of Badong and near the outlet of the Xiangxi River at the northern section on Xiannvshan Fault. In the region from the two sides of Shennong River in the north of Badong to the western Xietan, microseisms are distributed in three zones in near east-west direction, with steep and north-dipping sections, spreading along the high-to-low velocity transition zone of the P and S wave. On the northern section of Xiannvshan Fault, small earthquakes are distributed along the NNW-trending Xiannvshan Fault, and the geological section reveals a steep and linear distribution along the transitional zone between the high VP value area and the VS value that is low in the upper and high in the lower part. Joint inversion results show a good consistency of the planes of the microseisms with the distribution of active faults.

%U https://www.dzdz.ac.cn/EN/10.3969/j.issn.0253-4967.2016.02.008