关键词: 地震测深, 波速比, 速度结构, 地震活动

Abstract: In this paper,the structure of twodimensional crustmantle velocity and ratio of wave velocity γ is obtained by interpreting S wave data of depth seismic sounding profile alone Wenan—Yuxian—Cahayouzhongqi. The upper crust and middle crust is mainly made of granite, and all is brittle, the γ value for ratio of velocity is about 1.72 for the lower crust it is 1.78; and for the top of upper mantle it is 1.82. The result shows that the lower crust and the top of upper mantle have plastic features. In terms of the features of wave sets and lateral changes of γ, a few deep faults are inferred in this region. Combining with seismicity of this region, it is suggested that the occurrence of earthquakes is related to the structure as well as the character of rocks.

Key words: Seismic sounding, Ratio of wave velocity, Structure of velocity, Seismicity