Distortion effects caused by the target abnormal bodies in CSAMT exploration

PreviousNext No AccessInternational Workshop on Gravity, Electrical & Magnetic Methods and Their Applications, Xi'an, China, 19–22 May 2019Distortion effects caused by the target abnormal bodies in CSAMT explorationAuthors: Xian-Xiang Wang*Ju-Zhi DENGXian-Xiang Wang*Jiangxi Engineering Laboratory on Radioactive Geoscience and Big Data Technology, East China University of Technology, Nanchang, 330013, Jiangxi, ChinaSearch for more papers by this author and Ju-Zhi DENGJiangxi Engineering Laboratory on Radioactive Geoscience and Big Data Technology, East China University of Technology, Nanchang, 330013, Jiangxi, ChinaSearch for more papers by this authorhttps://doi.org/10.1190/GEM2019-026.1 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail Abstract In the CSAMT exploration, the use of the transmitter not only improves the signal-to-noise ratio (SNR) of the data, but also brings a series of distortion effects, such as shadow and source overprint effects. This paper attempts to introduce a distortion effect caused by the target anomaly in the measurement area. Although it is often ignored, it always plagues the data interpretation. With the introduction of the source, the primary current has determined direction. When the primary current encounters electrical interfaces, it will accumulate the induced charge at the interface, and generate local current, causing local distortion. It is stretched in the direction of the vertical primary current, and a false anomaly with opposite polarity appears on both sides of the abnormal body. Since the position of the induced charge accumulation is related to the direction of the primary current, when the direction of the primary current is different from the direction of the abnormal body, the behavior of the distortion effect is different. This paper confirms its existence by taking three simple models as examples, and explains it from the physical mechanism. On this basis, the paper summarizes the relationship between inversion and distortion, and believes that the relationship between distortion and inversion cannot be generalized. The forward part of the inversion can simulate the distortion effect, and it is not necessary to eliminate it before inversion. Otherwise, it must be eliminated. Keywords: electromagnetic, magnetic, resistivityPermalink: https://doi.org/10.1190/GEM2019-026.1FiguresReferencesRelatedDetails International Workshop on Gravity, Electrical & Magnetic Methods and Their Applications, Xi'an, China, 19–22 May 2019ISSN (online):2159-6832Copyright: 2019 Pages: 471 publication data© 2019 Published in electronic format with permission by the Society of Exploration Geophysicists and the Chinese Geophysical SocietyPublisher:Society of Exploration Geophysicists HistoryPublished Online: 28 Sep 2019 CITATION INFORMATION Xian-Xiang Wang* and Ju-Zhi DENG, (2019), "Distortion effects caused by the target abnormal bodies in CSAMT exploration," SEG Global Meeting Abstracts : 101-104. https://doi.org/10.1190/GEM2019-026.1 Plain-Language Summary KeywordselectromagneticmagneticresistivityPDF DownloadLoading ...