Distortion efects caused by target abnormal bodies in CSAMT exploration

• Autorzy: Wang Xian-Xiang , Deng Ju-Zhi , Ren Jing-Li

Identyfikatory

DOI

10.1007/s11600-020-00494-1

• Języki publikacji: EN

Abstrakty

EN

In CSAMT exploration, the using of the artifcial sources not only improves the signal-to-noise ratio of the data, but also brings a series of distortion efects, such as shadow and source overprint efects. This paper attempts to introduce a distortion efect caused by the target in the survey area. Although it is often ignored, it always plagues the data interpretation. In CSAMT method, the primary current has determined direction due to the source. When the primary current encounters electrical interfaces, the induced charge will accumulate on it and generate local current, causing local distortion. The anomaly body stretches in the direction of the vertical primary current, and a false anomaly with opposite polarity appears on both sides of the target. If the direction of the primary current is diferent, the accumulation position of the induced charge is also diferent, which will result in diferent shapes of the anomalies in observed data. This paper confrms the existence of the distortion by taking four simple models as examples and explains it from the physical mechanism. On this basis, the paper summarizes the relationship between inversion and distortion. If our code can simulate the distortion efect in the forward, we do not need to remove it before the inversion. Otherwise, it must be removed.

Słowa kluczowe

EN

distortion effect; galvanic effect; target abnormal body; controlled source audio-frequency magnetotellurics

PL

efekt zniekształcenia; efekt galwaniczny

• Wydawca: Instytut Geofizyki PAN ; Springer
• Czasopismo: Acta Geophysica
• Rocznik: 2020
• Tom: Vol. 68, no. 6
• Strony: 1653--1665
• Opis fizyczny: Bibliogr. 33 poz.

Twórcy

autor

Wang Xian-Xiang

• Jiangxi Engineering Laboratory on Radioactive Geoscience and Big Data Technology, East China University of Technology, Nanchang 330013, Jiangxi, China

autor

Deng Ju-Zhi

• Jiangxi Engineering Laboratory on Radioactive Geoscience and Big Data Technology, East China University of Technology, Nanchang 330013, Jiangxi, China

autor

Ren Jing-Li

• Jiangxi Engineering Laboratory on Radioactive Geoscience and Big Data Technology, East China University of Technology, Nanchang 330013, Jiangxi, China

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