小波分析与解析延拓方法相结合研究东海深部构造

东海是环太平洋活动构造带的重要组成部分,是探讨西太平洋边缘及边缘海形成演化的重要窗口。向上延拓主要用来削弱局部异常,突出深部异常,小波分析是重磁场位场分解的有效工具,不仅能提取深部异常,还能更好地将区域异常和局部异常分离。本文利用东海及邻域最新的布格重力异常数据资料,将小波分析与解析延拓方法相结合,分析对比向上延拓20 km的布格重力异常结果与小波分析4阶逼近布格重力异常结果,结合东海及邻域莫霍面的深度,对重力场及莫霍面深度进行初步研究。其中小波4阶逼近结果代表莫霍面形态,小波4阶细节结果代表东海及邻域凹陷凸起形态。

RESEARCH ON DEEP STRUCTURES OF EAST CHINA SEA BY COMBINING UPWARD CONTINUATION AND WAVELET ANALYSIS METHODS

East China Sea is an important part of West Pacific Tectonic Zone and a window to discuss the formation and evolution of west edge of the Pacific Ocean.Upward continuation has been used as a common method to process original gravity anomaly through strengthening deep anomaly and weakening local anomaly and it's important to deep structure research.Wavelet analysis is an effective tool to separate gravity and magnetic fields and it can not only extract deep anomaly but also separate regional and local anomalies.Based on the new Bouguer gravity anomaly data of East China Sea and adjacent regions,upward continuation and wavelet analysis methods were utilized in the present study.Bouguer anomaly results of 20 km upward and the 4th order wavelet approximation were compared and buried Moho depth was calculated and the characteristics of deep structures were analyzed.Anomaly of the 4th order wavelet approximation represents Moho and the 4th order detail wavelet result represents depression and uplift of East China Sea.