2013年9月，第19卷，第3期，504-512页 September 2013,Vol.19,No.3,p.504-512
高校地质学报
Geological Journal of China Universities
利用背景噪声反演鄂尔多斯块体及其
南缘地区地壳速度结构
陈强森，鲍学伟，徐树斌，王良书，徐鸣洁*
南京大学地球科学与工程学院，南京210093
摘要：文中利用分布在鄂尔多斯块体及其南部周缘地区的53个宽频带地震固定台站的连续波形记录，采用双台互相关计算方法由背景噪声提取瑞利波格林函数，经时频分析获得相速度和群速度频散曲线，并分别计算了汾渭地堑、秦岭北缘、鄂尔多斯块体内部和六盘山地区4个不同构造区的平均题散曲线，进而反演了各构造区的地壳上地慢一维横波速度结构。结果显示：地壳厚度在汾滑地暂为34km，在秦岭北缘地区和鄂尔多斯块体均为40km，在六盘山地区最厚，达49~50km；相应的上地顶部横波速度分别为4.20，4.2，4.30和4.15km/s；地壳内结构浅部特征差异最大，在地壳中部六盘山地区的速度较低，下部地壳不同地区的波速较一致。
关键词：背景噪声；格林函数；频散曲线；地壳上地慢速度结构；鄂尔多斯块体
文章编号：10067493（2013）03-504-09
中图分类号：P315.3
文献标识码：A
TheCrustalVelocityStructureoftheOrdosBlockanditsSouthernEdge
RevealedfromtheAmbientSeismicNoiseExtraction CHEN Qiangsen,BAOXuewei,XUShubin,WANGLiangshu,XUMingjie School of Earth Sciences and Engineering, Nanjing University, Nanjing 210093, China
Abstract: Using the dispersion curves of Rayleigh waves that were extracted from the seismic noise of 53 broadhand stations recorded in the Ordos Block and its southern Edge by two seismic stations cross correlation, we have obtained the average dispersion curve of the FenWei graben system, the Northerm edge of Qinling, the Ordos Block and the Liupan Mountains, and extracted the crustal and upper mantle structures of the four regions. The results show that the depth of the crust in the FenWei graben system, the northerm edge of Qinling and the Ordos Block, and the Liupan Mountains is 34 km, ~40 km, and 49~50 km, respectively. The velocity of S wave in the uppermost mantle of the corresponding region is 4.20 km/s, 4.25 km/s, 4.30 km/s, and 4.15 km/s. The most obvious difference of velocity structure appears in the upper crust. The Liupan Mountains has a low velocity in the middle crust. The characteristics of velocity are almost the same for the lower crust.
Key words: ambient seismic noise; Green function; dispersion curve; crust and upper mantle velocity structure; Ordos block
Corresponding author: XU Mingjie, Professor, E-mail: goxu@nju.edu.cn 收模日期：2012-06-20；修回日期：2012-09-10
基金项目：国家自然科学基金项目（41174038）资助
作者简介：陈强森，1987年生，男，地球物理专业硕土研究生；E-mail:chen1987qs@126.com
通讯作者：徐鸣活，女，教授，主要从事地球物理教学与研究；E-mail:goxu@nju.edu.c