An application of magnetotelluric data inversion in a stratovolcano region

Abstract

Sabalan, with an elevation of 4,811 meters, is the second-highest mountain located in the Alborz mountain range in northwestern Iran. Although it is an inactive stratovolcano, the overall system of faults around the Sabalan peak can be considered as two common groups of linear and arcuate faults. Faults with the linear structure are mainly observed along with the NW-SE and N-S directions at the southern part of Sabalan. Arcuate faults around the Sabalan volcano are almost coincided with the crater of the volcano and have led to the penetration of volcanic masses. In this study, magnetotelluric data modeling was performed on one profile ("namely the MM profile"). The profile includes both types of fault systems in the region. By assessing and interpreting the resistivity section of the MM profile by 2D magnetotelluric data inversion, we have clearly detected the faults by features such as displacement and sudden changes in resistivity anomalies forming conductive zones with low resistivity anomaly along with the profile. The MM profile has almost continuous conductive anomaly (<30 Ω-m) between elevations of 1000 to 3000 m except in the eastern side, where a resistive block is found from the surface down to lower depths. Eight faults were detected across the MM profile. Our final represented geology section is consistent with actual observations and 2D magnetotelluric data inversion and prior studies.

Analysis of two-dimensional magnetotelluric inversion for the delineation of the petroleum system in the Kutai basin, East Kalimantan, Indonesia

“…In the 1-dimensional medium, there are EM field components in the horizontal direction (Ex, Ey, and Hy, Hx) that vary only with depth (not varying with x-axis and y-axis) and there are no vertical EM field components [30]. Based on the orthogonal nature of induction between the electric field and the magnetic field and the same properties in Ex and Ey as well as in Hx and Hy, the discussion of EM components in this medium is one of them in Ex and Hy [31].…”

Groundwater exploration by magnetotelluric method within the birimian rocks of mankessim, Ghana

“…This method was chosen because the Electrical Tomography cannot achieve deeper targets and the Electrical Vertical Sounding cannot ensure complete and dense space coverage but the Magnetotelluric method can be used for great depths of investigation, good space sampling, as well as differentiate between salt-saturated water and freshwater layers. The use of this method in groundwater studies and other geoscience investigation is common globally as they are well documented in the literature (Tinlin et al 1988;Brasse 1989;Bernard et al 1990;Bartel 1991;Chouteau et al 1994;Nichols et al 1994;Bourgeois et al 1994;Dennis et al 2011;Chave and Jones 2012;Nittinger and Becken 2016;Amjadi et al 2020;Muttaqien and Nurjaman 2021). MT is a passive induction-based electromagnetic method that uses the naturally occurring electromagnetic field in detecting resistivity variations within the earth's materials (Simpson and Bahr 2005).…”