In order to study the effective detection depth of the wide field electromagnetic method (WFEM) under the condition of transition zone, the authors designed four geoelectrical models, i.e., homogenous half space, two layers section, three layers section and four layers section, with the skin depth-apparent resistivity curves obtained by forward calculation. Taking magnetotelluric sounding (MT) for reference, the authors made a comparative study of the detection depth of the wide field electromagnetic method and the controlled source audio magnetotelluric method (CSAMT) at the same transmit-receive distance. The results show that the wide field electromagnetic method can be measured in the transition zone and can get larger detection depth with the smaller transmit-receive distance.
郑冰. 过渡区条件下广域电磁法探测深度问题的理论研究[J]. 物探与化探, 2016, 40(1): 78-82.
ZHENG Bing. A theoretical study of the detection depth of WFEM under the condition of transition zone. Geophysical and Geochemical Exploration, 2016, 40(1): 78-82.
[1] Tikhonov A N. On determining electrical characteristics of thedeep layers of the earth's crust, Geophysics Reprint Series No.5:Magnetotelluric Methods[C]//Vozoff K. Tulsa, Oklahoma:Society of Exploration Geophysicists, 1989:2-3.[2] Cagniard L. Basic theory of the magneto-telluric method ofgeophysical prospecting[J]. Geophysics, 1953, 18(4):605-635.[3] Goldstein M A, Strangway D W. Audio-frequencymagnetitellurics with a grounded-electric dipole source[J].Geophysics, 1975, 40(4):669-683.[4] Goldstein M A. Magnetotelluric experiments employing artificial dipole source[D]. Ontario:University of Toronto, 1971.[5] 何继善.可控源音频大地电磁法[M].长沙:中南工业大学出版社,1990.[6] 汤井田,周聪,肖晓.复杂介质条件下CSAMT最小发收距的选择[J].中国有色金属学报,2013,23(6):1681-1693.[7] 林威.CSAMT法过渡区电磁场的特征[J].物探与化探,2009,33(2):148-150.[8] 杨生,施婉华,王庆乙.CSAMT的非远场改正和二维解释问题[J].地质与勘探,1993,29(9):42-48.[9] 周茂军,周玉冰.可控源音频大地电磁法(CSAMT)的近场效应和近场校正[J].辽宁地质,1993,(3):272-281.[10] 詹少金,钱美平,冯戋戋,等.CSAMT全区视电阻率电场正演迭代拟合近场校正方法[J].物探与化探,2011,35(5):663-665.[11] 陈明生,闫述.CSAMT勘探中场区、记录规则、阴影及场源复印效应的解析研究[J].地球物理学报,2005,48(4):951-958.[12] 岳瑞永,徐义贤.可控源频率域电方位各向异性与近场效应研究[J].石油地球物理勘探,2004,39(3):342-347.[13] 何继善.广域电磁测深法研究[J].中南大学学报:自然科学版, 2010, 41(3):1065-1072.[14] 何继善.广域电磁法和伪随机信号电法[M].北京:高等教育出版社,2010.
