利用二维经验模态分解提取川滇地区流动重力异常特征

The Extraction of Abnormal Feature of Mobile Gravity in the Sichuan-Yunnan Region Using BEMD Method

首先介绍二维经验模态分解(BEMD)方法的基本原理及其关键技术,然后利用模型试验验证BEMD方法分解得到的各分量的实际地质含义,最后将该方法应用到川滇地区2015-09~2016-09流动重力差分动态变化异常多尺度分解中,并对提取的各尺度异常进行分析解释,各分量异常通过重构实现分场。结果表明,湮没在区域异常中的某频率范围内"弱异常"经过分离异常幅值相对增强,区域性异常变化特征更加明显。

In this paper, firstly, we introduce the basic principle and the key technology of BEMD method; Secondly, the model test proves that the bi-dimensional intrinsic mode function （BIMF） at all levels and the residue by BEMD method, which own their practical geological meaning; Lastly, the BEMD method is innovatively applied to deal with the mobile gravity anomalies of differential dynamic variation of the period of 2015-09~2016-09 so as to obtain the multi-scale decomposition and the extracted anomalies at all levels are analyzed, and then we reconstruct the local and region anomalies with BIMFs and residue, and the results show that the weak anomalies in the region area at a certain frequency range decomposed by BEMD method, can be enhanced relatively, the regional anomaly characteristics become more obvious, and then we can propose the suggestion about the earthquake trend according to the features of abnormal changes.