scholarly journals Analysis for Geoelectric Strike Direction of Magnetotelluric Data from a Geothermal Area

Author(s):  
G Yogasatria ◽  
H Grandis
Geophysics ◽  
1976 ◽  
Vol 41 (4) ◽  
pp. 766-770 ◽  
Author(s):  
F. E. M. Lilley

Observed magnetotelluric data are often transformed to the frequency domain and expressed as the relationship [Formula: see text]where [Formula: see text] [Formula: see text] and [Formula: see text] [Formula: see text] represent electric and magnetic components measured along two orthogonal axes (in this paper, for simplicity, to be north and east, respectively). The elements [Formula: see text] comprise the magnetotelluric impedance tensor, and they are generally complex due to phase differences between the electric and magnetic fields. All quantities in equation (1) are frequency dependent. For the special case of “two‐dimensional” geology (where structure can be described as having a certain strike direction along which it does not vary), [Formula: see text] with [Formula: see text]. For the special case of “one‐dimensional” geology (where structure varies with depth only, as if horizontally layered), [Formula: see text] and [Formula: see text].


Geophysics ◽  
2005 ◽  
Vol 70 (2) ◽  
pp. G33-G41 ◽  
Author(s):  
L. B. Pedersen ◽  
M. Engels

Recent developments in the speed and quality of data acquisition using the radiomagnetotelluric (RMT) method, whereby large amounts of broadband RMT data can be collected along profiles, have prompted us to develop a strategy for routine inverse modeling using 2D models. We build a rather complicated numerical model containing both 2D and 3D elements believed to be representative for shallow conductors in crystalline basement overlain by a thin sedimentary cover. We then invert the corresponding synthetic data on selected profiles, using both traditional MT approaches, as well as the proposed approach, which is based on the determinant of the MT impedance tensor. We compare the estimated resistivity models with the true models along the selected profiles and find that the traditional approaches often lead to strongly biased models and bad data fit, in contrast to those using the determinant. In this case, much of the bias is removed and the data fit is improved. The determinant of the impedance tensor is independent of the chosen strike direction, and once the a priori model is set, the best fitting model is found to be practically independent of the starting model used. We conclude that the determinant of the impedance tensor is a useful tool for routine inverse modeling.


2011 ◽  
Vol 32 (6) ◽  
pp. 654-664
Author(s):  
Seong-Kon Lee ◽  
In-Hwa Park ◽  
Yong-Hyun Chung ◽  
Tae-Jong Lee

Heliyon ◽  
2021 ◽  
pp. e07440
Author(s):  
Hakim Saibi ◽  
Sadieh Khosravi ◽  
Biruk Abera Cherkose ◽  
Maxim Smirnov ◽  
Yosef Kebede ◽  
...  

2013 ◽  
Vol 448-453 ◽  
pp. 3788-3791
Author(s):  
Bo Li ◽  
Wen Bo Wei ◽  
Le Tian Zhang

The cental Asian orogenic belt (CAOB) which between the North China Craton and the Siberian Craton is one of the tectono-metallogenic belts in the world. The central Inner Mongolia belongs to the eastern part of the CAOB, recently a series of research and exploration work has been done in this region. However, no breakthrough has been made in the exploration of metal ore. In order to research current mineralization issues in the eastern part of the CAOB, a long magnetotelluric (MT) profile was acquired across the central part of Inner Mongolia. The profile starts within the DongUjimqinqi in the northwest, goes southeastward across the Chagan Obo-Arongqi fault, the Erenhot-Hegenshan fault, the Xilinhot fault and the Linxi fault, and ends around the Xar Moron fault in the northern part of Chifeng city; the strike direction of most faults is southeast; the faults have direct control effect to the magmation and mineralization of this region. The model of electrical structure along the profile can be divided into two regions: widely distributed low resistivity is the key feature north of Nianzigou; high resistance is the key feature south of Nianzigou. The Chagan Obo-Arongqi fault, the Erenhot-Hegenshan fault and the Xilinhot fault all present as a southeastward dipping conductor, which reflects their overthrusting process; there are many high conductivity areas along the faults in the region. The electrical structure to the south of Nianzigou is expressed as a mushroom shape, which reflects the tectonic origin of magmatic rock in this region.


2015 ◽  
Vol 13 (4) ◽  
pp. 397-408 ◽  
Author(s):  
V. Spichak ◽  
J. Geiermann ◽  
O. Zakharova ◽  
P. Calcagno ◽  
A. Genter ◽  
...  

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