山西地区地壳S波速度结构

利用山西及周边共44个宽频地震台2014-01~07地震噪声数据，反演瑞利波群速度和相速度频散，得到研究区域的三维剪切波速度。上地壳中，山西断陷带表现为较低的速度异常，而两侧的隆起区则显示高速异常；中下地壳主要表现为以北纬38.5°左右为界的南高北低的速度特征。大同盆地从浅部到中下地壳整体呈现为低速特征，与该地区广泛存在的火山群有关。

The Crustal S-Wave Velocity Structure of Shanxi Region

In this paper, we use ambient noise tomography to study the Shanxi regional crustal velocity structure and deep tectonics.The data includes 7 months (2014 January to 2014 July) three-component continuous data recorded at 44 seismic stations of Shanxi province digital seismic networks and its surrounding . The S-wave velocity structure of the crust is inverted from Rayleigh wave dispersion maps. The S-wave velocity maps show clear lateral variations that correlate well with major geological structures and tectonic units in the study regions: in the upper crust, S-wave velocities of the Shanxi fault depression zone are relatively low at shallow depth, while the uplifts on sides of Shanxi fault depression zone show high velocity. In the mid-lower crust, the latitude ~38.5°N divides the region into a northern part with a low velocity anomaly and a southern part with a high velocity anomaly. Datong basin shows low velocity in the crust,possibly related to the wide distribution of volcanoes.