远震层析成像在柴西狮子沟构造背景研究中的应用

An application of teleseismic tomography to the study of the shallow structures beneath Shizigou in western Qaidam basin

利用2004—2007年在柴达木盆地西部狮子沟地区布设的地震台站的连续观测资料,挑选远震P波到时,采用远震体波走时层析成像方法进行反演处理,获得了该地区地下三维速度结构图象.反演结果表明,在研究观测地区西南侧存在一近北西走向的低速异常体,以较大倾角向北东方向插入;在该低速异常体的北部、东北部和东部环绕着相对高速的异常,其走向和分布范围基本与狮子沟背斜构造一致.

Using teleseismic body wave traveltime tomography to invert the picked P-wave traveltimes, the images of three dimensional seismic velocity structure are obtained for the Shizigou region in western Qaidam basin. The seismic data we used were continuously recorded on the stations deployed during 2004-2007 in Shizigou region. The inversion result indicates tnat there is a NW-trending low velocity anomaly beneath the study region. This anomaly inclines toward northeast in a high dipping angle. The low velocity anomaly is surrounded by a high velocity anomaly to the north, the northeast and the east. The strike and the coverage of the high anomaly coincide well with the Shizigou anticline.