基于背景噪声面波的吉林省东南部S波速度结构成像

S-wave velocity structure tomography based on ambient noise surface wave in southeastern part of Jilin Province

为研究吉林省东南部地区的S波速度结构,笔者使用吉林、黑龙江和辽宁测震台网共计39个固定台站的重采样连续波形数据,利用台站对的背景噪声互相关计算瑞利面波的经验格林函数,提取群速度和相速度频散曲线,用面波成像方法获得研究区深度为0~30km的S波速度结构图像。成像结果表明:吉林省东南部地区地壳深度内的S波速度结构具有较强的横向不均匀性特征。研究区上地壳的速度异常与沉积盆地、断裂带和造山带等地质构造有较好的对应,中下地壳的速度异常表现了火山活动和岩浆作用的特征。

In order to study the S-wave velocity structure in the southeastern part of Jilin Province,the authors use the resampled continuous waveform data of 39 fixed stations in the Jilin,Heilongjiang and Liaoning seismic networks,calculate the empirical Green function of Rayleigh surface wave by using the ambient noise cross-correlation of station pairs,extract the group velocity and phase velocity dispersion curve,and obtain the S-wave velocity structure image of the study area with a depth of 0~30 km by using the surface wave tomography method.The tomography results show that the S-wave velocity structure in the crust depth of the southeastern part of Jilin Province has strong lateral heterogenous characteristics.The velocity anomaly of the upper crust in the study area corresponds well with the geological structures such as the sedimentary basin,fault belts and orogenic belts,while the velocity anomaly of the middle and lower crust shows the characteristics of volcanic activities and magmatism.