Abstract: The S-wave data are selected from the records of 1 946 earthquakes observed in the period from 1984 to 1993 by seismic network in the zone of 104～112°E, 31.5～38°N in Shaanxi, Shanxi, Henan, Hubei, Gansu and Ningxia Provinces.The S-wave velocity image of the crust beneath the Weihe downfaulted basin and adjacent areas is obtained by means of seismic tomographic technique. The results show that the non uniform S-wave velocity structure of deep crust is closely related to the difference of geotectonic element,fault structure and seismic activity.

Key words: Weihe graben system, Seismic tomography, S-wave, Velocity structure

摘要： 选取104～112°E,32.5～38°N区域内陕西、山西、河南、湖北、甘肃、宁夏等省区的区域地震台网1984～1993年的1946个天然地震的S波观测资料,用地震层析成像方法反演了渭河断陷及其邻近地区的地壳S波速度图象,其结果表明地壳深部S波速度结构的不均匀性与该区大地构造单元、断裂构造及地震活动密切相关。

关键词: 渭河地堑系, 地震层析成像, S波, 波速构造