Mobile magnetotelluric facilities MTMOB

Fluctuations in the Earth’s naturally occurring external magnetic field induce electrical currents in the Earth. The magnetotelluric (MT) method exploits these induced electrical currents to determine the electrical conductivity structure of the crust from the near surface hundreds of meters to depths of several hundred kilometers. MT with its wide depth range, is ideally suited for addressing fundamental problems in solid earth studies over multiple depth scales including; shallow geothermal and mineral exploration, magmatic and volcanic systems, through large scale tectonic investigations. From surface measurements of the two horizontal components of the electric and magnetic fields, denoted by vectors E and H, respectively, as well as the vertical component of the magnetic field, Hz, transfer functions in the frequency domain can be determined, defined by E = ZH and Hz = -K•H. Here, Z is the 2×2 impedance matrix, and K is the induction vector, both of which are complex functions of the earth’s conductivity σ (or resistivity ρ=1/σ). The distribution of resistivity is estimated by non-linear inversion of these functions.

MTMOB maintains two Metronix-GMS06 and two Metrinics-GMS07e wideband systems for lithospheric imaging studies and two LEMI-417 long period MT systems for research of deeper regions. IG-CAS researchers are currently using MT studies to investigate: both active and fossil tectonic processes, magmatic systems, geothermal resource potential, and metal endowment.

Mapa