among all the geophysical techniques, the magnetotelluric method has improved considerably in recent years and is widely being used in hydrocarbon exploration especially in regions where reflection seismic has difficulties. areas which are covered with high velocity rocks in the near surface are most popular cases. a huge high resolution magnetotelluric investigation was conducted in the sehqan...

During the Tasman Project of Seafloor Magnetotelluric Exploration recordings were made of the natural magnetic and electric field variations along a line of seafloor sites crossing the Tasman Sea. Using these data and additional magnetic field recordings made on the Australian continent the pattern of geomagnetic induction in the Tasrnan Sea Region is examined. An investigation of the seafloor ...

The usual methodology used in magnetotelluric signal processing (MT) has been studied and applied to the case of audio-magnetotellourics (AMT). The results obtained have proved not to be good enough in order to obtain a good subsurface resistivity model. Therefore, some changes have been made to the methodology of signal processing so that it suits audio-magnetotellurics. These changes have app...

The magnetotelluric (MT) method has become more widely used in hydrocarbon exploration. The inversion of MT data, which can determine the electrical structure of subsurface, is a nonlinear and multimodal optimization problem. Particle swarm optimization(PSO) algorithm is a good solver for this geophysical inversion problem, whereas it has a shortage of heavy computation time. An improved parall...

We present a new formulation of the hybrid method for threedimensional (3D) electromagnetic (EM) modeling in complex structures with inhomogeneous background conductivity (IBC). This method overcomes the standard limitation of the conventional IE method related to the use of a horizontally layered background only. The new method allows us to compute the effect of IBC structures by using any app...

The natural-source magnetotelluric (MT) technique has one major advantage over all other electrical or electromagnetic (EM) methods: namely that the skin depth phenomenon ensures that all depths can be probed using MT data, albeit with decreasing resolution with depth due to the intrinsic spatiallyaveraging filter of the method. Thus, one can tune MT for the depth of interest and use the same p...

The Solar Quiet (Sq) day source current were calculated using the magnetic data obtained from a chain of 10 magnetotelluric stations installed in the African sector during the French participation in the International Equatorial Electrojet Year (IEEY) experiment in Africa. The components of geomagnetic field recorded at the stations from January-December in 1993 during the experiment were separ...

We used magnetotelluric data from 352 sites in Botswana to derive a country-wide electrical conductivity model of the crust and upper mantle structure. A robust methodological scheme 3D inversion were with unprecedented spatial coverage. The results show interesting features, including major cratonic blocks mobile belts Botswana. distinctive resistive structure was imaged southwest Botswana, wh...

A magnetotelluric monitoring station has been installed in the Val d’Agri area (southern Italy), to investigate the physics underlying the generation mechanisms of the electrokinetic effect, due to rapid pore pressure changes and fluid flows near the focal area of incoming earthquakes. It is well known that the magnetotelluric method reveals variations in electrical resistivity within the Earth...