摘要
海洋深部地壳结构研究 ,主要研究沉积基底面与莫霍面的形态与埋深 .这两个界面 ,上、下地质体的密度差异分别约为 0 .1g/cm3和 0 .4g/cm3,采用重力测量成果来研究这两个界面 ,具有充分的物性前提 .但是 ,重力测量成果是整个岩石圈甚至包括上地幔物质的综合反映 ,如果能从测量成果中分离得到上述两个界面的重力效应 ,再据此来研究它们的形态 ,就会简单、准确一些 .我们采用二维小波多尺度分解技术 ,首次对东海及邻区自由空间重力异常进行分解 ,目的在于获取沉积基底面、莫霍面所产生的重力异常 .对分解结果进行了分析研究后认为 ,四阶变换异常细节主要由沉积基底面的起伏引起 ,四阶变换异常逼近则主要由莫霍面的起伏所引起 .本文介绍了二维小波多尺度分解方法与算法 ,展示了分解结果 ,论述了对分解结果的初步认识 .
The sedimentary basement and Moho besement are important interfaces in the crust of ocean,and their forms and depths have been extensively studied. Because the density contrasts of the two basement about 0.1g/cm 3 and 0.4g/cm 3 are prominent, the gravity values are used to study the basements.However, the gravity anomalies include the contributions from whole lithosphere and upper mantle,the decomposition of the gravity field is important.In this paper we apply the wavelet analysis to decompose the gravity field.In order to obtain the gravity anomalies correlated with the sedimentary and Moho basements, we decomposed the free air gravity anomalies of East China Sea and adjacent regions by using the two dimensional wavelet decomposition technique. The results show that the fourth order detail of the free air gravity anomalies mainly reflects the sedimentary basement, while the fourth order approximation of the free air gravity anomalies reflects the Moho. [
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2000年第6期842-849,共8页
Chinese Journal of Geophysics
基金
国家科学技术部863计划资助项目(820-01-03-02)
关键词
东海及邻区
自由空间重力异常
小波多尺度分解
沉积基底面
莫霍面
East China Sea and adjacent regions,Free air gravity,Multiscale decomposition of wavelet,Sedimentary basement,Moho basement
