Journal of Geophysics and Engineering, 2009, 6(3): 279-287

Regional gravity anomaly separation using wavelet transform and spectrum analysis

Ya Xu, Tianyao Hao, Zhiwei Li, Qiuliang Duan and Lili Zhang

Abstract

In this paper, we propose the separation of the regional gravity anomaly using wavelet multi-scale analysis and choose rational decomposition results based on the spectrum analysis and their depth estimation results. The isotropic, symmetrical and low-pass wavelet filter, Halo wavelet, is used for wavelet transform and regional anomaly separation. The anomaly separation method is verified by the synthetic model of combined cuboids. It has also been used for regional gravity separation and deep structure study in the Dagang area, North China. The regional anomalies are obtained from large-scale wavelet decomposition results. The average depths estimated from the radial power spectrum and the stratum density are used to establish the relationship between the separation anomaly and buried geologic units. The results from seismic data and magnetotellurics inversion are used to assist the regional anomaly interpretation. From the wavelet analysis and spectrum comparisons, the regional anomalies caused by Moho and Cenozoic basement are given for further deep structure analysis.