利用噪声记录估计福建地区中上地壳体波速度结构

The wave velocity structure of upper shell in Fujian estimated by the noise records

摘要:

本文利用福建地震台网25个宽频带台站的噪声记录提取瑞利波和勒夫波频散曲线反演地壳波速结构,并利用爆破观测结果对该速度模型进行检验。结果表明:利用该方法得到的地壳波速结构在浅部分辨率较好,深部波速结构的反演结果精度较低,这主要是由于本文所选台站间距较小,提取得到的面波频散曲线在短周期部分精度较高,而长周期部分面波频散曲线的偏差较大。综合噪声反演结果与传统反演结果,本文最终给出了一个新的速度模型,利用该模型计算得到的理论走时与爆破观测走时具有很好的一致性。

Abstract:

The dispersion curves of Rayleigh wave and Love wave were extracted from the seismic noise of 25 broad-band stations recorded by the Fujian Seismic Network, and inverted for the lithosphere wave structure. Furthermore, the velocity model was inspected by the blast observation outcome. The results indicate that the resolution of the lithosphere wave structure obtained by this method is good in the shallow part, but in the depth part the inverted result of the wave structure has low precision. It is mainly caused by the small inter-station distance chosen in the paper. So the wave dispersion curves have high precision in short-period part, but the warp of the wave dispersion curve in long-period part is big. Considering both the results of the noisy invert and the traditional invert, we finally present a new velocity model in which the theory calculated runtime can well match the blast observation runtime.