Regional Geoelectrical Dimensionality of the Northwestern Part of Turkey From Magnetotelluric Tensor Invariants

Abstract

In this study, measurements obtained through the first two profiles from the TÜBİTAK (The Scientific and Technological Research Council of Turkey) project titled "Research of the Crustal Structure of Northwestern Anatolia with Geophysical Methods" from 2007 were used. Magnetotelluric (MT) measurements were taken from 174 sites approximately every 3 km in the region between Zonguldak and Akşehir (Konya). Dimensionality analysis was conducted with the decomposition of the impedance tensor obtained through the measurement data from the two profiles. The relationship between the observed geo-electric behaviors, the geological structure of the area and the MT dimensionality changes were detected. Two-dimensional (2D) and three-dimensional (3D) structures were revealed as a result of the dimensionality analysis obtained through the MT data from the region located between Zonguldak and Akşehir. The dimensionality was observed to be complex in small periods due to the heterogeneous conductive materials close to the surface and 3D structures were observed to be predominant in high periods. Moreover, the dimensionality near the suture zones were observed to be more complex compared to other areas according to the dimensionality analysis results. The structures in the vicinity of the North Anatolian Fault were found out to be N-NE striking. This indicates the accuracy and reliability of the results.