电导率连续变化二维海洋大地电磁场自适应有限元正演研究  

Adaptive finite element forward modeling of marine MT fields in a 2D structure with a linear variation of conductivity

作　　者：潘林冬 李予国[1,2] 赵慧 PAN Lindong;LI Yuguo;ZHAO Hui(College of Geosciences,Ocean University of China,Qingdao 266100,China;Key Lab of Submarine Geosciences and Prospecting Techniques of Ministry of Educaion,Ocean University of China,Qingdao 266100,China;National University of Defense Technology,Changsha 410073,China)

机构地区：[1]中国海洋大学海洋地球科学学院,青岛266100 [2]海底科学与探测技术教育部重点实验室,青岛266100 [3]国防科技大学,长沙410073

出　　处：《物探化探计算技术》2018年第1期54-63,共10页Computing Techniques For Geophysical and Geochemical Exploration

基　　金：国家自然科学重点基金项目(41130420)

摘　　要：岩矿石在形成过程中受湿度、含水率、温度、压力等多种外界因素的影响,这些因素会导致岩矿石的电导率连续变化,于是电导率连续变化地电模型可能更符合实际地质情况。对电导率连续变化二维介质大地电磁场分布规律,进行了有限元正演数值模拟研究。基于自适应有限元模拟技术和非结构网格剖分技术,使得新的算法可以真实地模拟电导率连续变化的复杂二维地电模型,并能够提供高精度的数值解。算例表明,海底近地表垂向电导率发生变化能够对高频大地电磁场响应产生较大影响。The conductivity of rocks and minerals are affected by several environmental parameters such as humidity,moisture,temperature,pressure and so on.These factors may lead to continuous variation of conductivity of rocks and minerals.In this paper,we present an adaptive finite element method for marine magnetotelluric fields in 2D structures with continuously varying conductivity.Our algorithm is implemented on an unstructured triangular mesh,which allows to simulate complex geoelectric models and can provide accurate numerical results.The numerical examples show that magnetotelluric responses at high frequencies can be significantly affected by the conductivity variation near the surface.

关 键 词：电导率连续变化 自适应有限元 非结构网格 大地电磁 正演 

分 类 号：P631.2[天文地球—地质矿产勘探]