over the past three decades helicopter-borne electromagnetic (hem) measurements have been used to reveal the resistivity distribution of the earth's subsurface for a variety of applications. hem systems include a “bird” or sensor containing one or more pairs of transmitting and receiving coils. the separation between the rigidly mounted transmitting and receiving coils of a coil-pair typic...

generally, the measured secondary field data is inverted into resistivity using two principal models; the homogeneous half-space model and the layered half-space model. while the homogeneous half-space inversion uses single frequency data, the inversion is done individually for each of the frequencies used, the multi-layer 1d inversion is able to take the data of all frequencies available into ...

a detailed standard magnetotelluric (mt) study was conducted to recognize brine bearing layers in depths of less than 2000 m in the northeast of iran close to the southeastern shore of the caspian sea. long and medium period natural-field mt methods have proved very useful for subsurface mapping purpose by determining the resistivity of the near surface structure. mt data were analyzed and mode...

tehran, the capital of iran, is under the threat of large magnitude earthquakes (above 7) located on known active faults. previous studies on the effect of local surface geology on earthquake ground motion using 1d calculation of sh transfer function (jafari et al., 2001; jica & cest, 2000) and using experimental methods (haghshenas, 2005) based on earthquake and ambient noise vibration recordi...

magnetotelluric (mt) method is an electromagnetic method which provides information about subsurface conductivity structures using earth's natural electromagnetic fields. static shift is one of disorders arising from shallow conductors; therefore static shift must be corrected as one of mt data processing steps. in the absence of sufficient information about the near surface distortions, w...

In this paper, we studied effect of different parameters including density, viscosity, interfacial tension and solute transfer concentration on phase inversion hold-up. The results showed that change in phase density ratio had no effect on phase inversion hold-up. It also disclosed that the phase viscosity ratio was the most effective parameter affecting phase inversion hold-up and each phase h...