Magnetotellurics | Sabri Bülent Tank, Ph.D.

Title

Prof.Dr.

Email Address

bulent.tank [at]

[at]

bogazici.edu.tr

Phone Number

+90 216 516 32 41

About

Attention

I am happy to recieve the

"Excellent Reviewers Award" (2025) given by

the Earth, Planets and Space (EPS) Editorial Board.

Certificate

Attention

Alert

!!! New publication alert !!!

Exposing electrical conductivity anomalies beneath Mount Erciyes, Cappadocia, Türkiye,

Journal of Volcanology and Geothermal Research, Volume 467, November 2025, 108428.

Alert

Professor of Geophysics @ Department of Geophysics, Boğaziçi University’s Kandilli Observatory and Earthquake Research Institute.

bulent.tank@bogazici.edu.tr

I am a geophysicist specializing in electromagnetic induction in the earth and the magnetotellurics (MT) method. Trained at the Tokyo Institute of Technology as a MEXT and JSPS scholar, my research applies MT to map the structure and dynamics of the Earth's subsurface. My work deciphers the multi-physics of active and passive fault zones, volcanic systems, and deep Earth processes, addressing three core areas in applied geophysics:

Faults: I apply advanced electromagnetic imaging techniques to resolve the structural geometry and fluid distribution in the vicinity of active/passive faults. Starting with 1999 Izmit earthquake, I studied several fault segments along the North Anatolian Fault (NAF). I worked on the NAF near Düzce, Ganos, Balıkesir, Tosya etc. Please click here to see relevant articles.
Hydrothermal & Geothermal Systems: My research on the geothermal systems targetted to map the reservoir structures to optimize the exploration and sustainable development of geothermal energy. I worked on several geological features in the Aegean and Cappadocia. Please click here to see relevant articles.
Volcanoes: Employing electromagnetic (EM) techniques, I monitored magma plumbing systems and fluid pathways for enhanced hazard assessment. I resolved the electric structure beneath several volcanic bodies such as Mt.Hasan and Mt. Erciyes in Central Anatolia (within the NSF funded project Continetal Dynamics/Central Anatolian Tectonics - CD/CAT) and . Please click here to see relevant articles.

Additionally, in the early days of my career, before focusing on the electromagnetic induction studies, I worked on Geomagnetism. In particular, during my M.Sc. I studied the westward drift of the non-dipole part of the Earth's main magnetic field which gives information on the CMB (Earth's core-mantle boundary). Moreover, I attended experiments in which we tested the effect of Solar eclipse on the Earth's external magnetic field. Please click here to see relevant articles.

MT site

Magnetotellurics

MT site

The Magnetotelluric (MT) method is a passive electromagnetic (EM) geophysical exploration technique used to image the subsurface electrical conductivity structure of the Earth from depths of a few tens of meters down to the upper mantle (several hundred kilometers). It relies on measuring natural fluctuations in the Earth's magnetic and electric fields.

High Frequencies (>1 Hz): Sourced from lightning activity (sferics) in the atmosphere.
Low Frequencies (<1 Hz): Sourced from the interaction between solar wind and the Earth's magnetosphere.

These time-varying magnetic fields induce telluric (electric) currents in the ground. By measuring these induced fields simultaneously, the method determines the Earth's electromagnetic impedance.

A standard MT station typically records five components. The electric fields (Ex,Ey) are measured using non-polarizable electrodes (porous electrodes) connected by wires laid out in an L-shape (North-South and East-West). The magnetic fields (Hx,Hy,Hz) are measured using induction coils or fluxgate magnetometers.