干旱区生态环境知识资源中心(Arid): 大地电磁测深中大地电场的高精度采集技术

Arid

	大地电磁测深中大地电场的高精度采集技术
其他题名	High-precision acquisition technology of telluric field on magnetotellurics
	王辉 1; 叶高峰 2; 魏文博 2; 金胜 2; 张巍 1
来源期刊	地球物理学进展
ISSN	1004-2903
出版年	2013
卷号	28 期号:3 页码:1199-1207
中文摘要	大地电磁测深需要采集正交的天然电磁场信号,其中大地电场信号微弱且易受环境噪声影响.为了提高大地电场的测量精度,本文通过试制新型Pb-PbCl_2不极化电极和改变电极的掩埋方式,室内和野外对比实验结果表明:试制电极具有级差小、稳定时间长的优点;采用加桶加水的方式掩埋电极,不仅可以提高电极极差的稳定性,还有利于减小电极极差突变的机率;电极掩埋深度对电极的稳定性影响很大,深埋电极可以有效抑制电极极差的漂移.另外,野外大地电磁数据采集时难免会遇到了一些沙漠、河流等特殊地形,采用传统的测量方式无法采集到精确的大地电场信号,本文通过对比实验,总结了在特殊地形条件下大地电磁信号采集的技术要点,如在沙漠地区,电极坑中应加入大量泥浆以减小电极的接地电阻,当测点在河流附近时,电极对不应跨过河面,减小自然电位对大地电场的影响.
英文摘要	Magnetotelluric(MT)sounding method measures the orthogonal natural telluric and magnetic signals. The telluric field is generally weak and apt to be contaminated by noise.The accuracy of telluric field measurement determines the quality of MT data.In order to obtain high-precision telluric field data,in this study,we discuss on how to improve the measurement accuracy from three aspects.Firstly,we investigated the reasons causing the variation of electric potential difference of non-polarizable electrodes,which were wildly used for acquiring telluric filed and developed Lead-Lead Chloride electrodes.The test results of comparison with other electrodes showed that,the new type of electrodes have lower potential difference and longer stable duration.The field experiments results show that we can get longer period signals by applied the self-made electrodes and improve the MT data quality.Secondly,given that the burying depth of electrodes also affects the stability of potential difference,we conducted a series of experiments on different burying depths.The results show that burying electrodes with deeper depth can reduce the variation of potential difference,and burying electrodes in a bucket with water can enhance the stability and reduce the rate of sharp change of potential difference.Furthermore,funded by project SinoProbe-01, we have acquired a large amount of MT field data.During the process of data acquisition,we found it was hard to get high quality MT data in some specific environments,such as deserts or swampy lands.Through a series of comparative experiments,we summarize in this paper several technical means to enhance the quality of telluric field data acquisition,such as burying electrodes deeply with bentonite and salt water in desert places.
中文关键词	大地电磁测深 ; 大地电场 ; 不极化电极
英文关键词	Magnetotelluric sounding Telluric field Non-polarizable electrodes
语种	中文
国家	中国
收录类别	CSCD
WOS类目	GEOSCIENCES MULTIDISCIPLINARY
WOS研究方向	Geology
CSCD记录号	CSCD:4868559
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/229375
作者单位	1.中国地质大学(北京)地球物理与信息技术学院, 北京 100083, 中国; 2.中国地质大学(北京)地球物理与信息技术学院, 地质过程与矿产资源国家重点实验室;;地下信息探测技术与仪器教育部重点实验室, 北京 100083, 中国
推荐引用方式 GB/T 7714	王辉,叶高峰,魏文博,等. 大地电磁测深中大地电场的高精度采集技术[J],2013,28(3):1199-1207.
APA	王辉,叶高峰,魏文博,金胜,&张巍.(2013).大地电磁测深中大地电场的高精度采集技术.地球物理学进展,28(3),1199-1207.
MLA	王辉,et al."大地电磁测深中大地电场的高精度采集技术".地球物理学进展 28.3(2013):1199-1207.