The inversion of electromagnetic sounding data does not yield a unique solution, but inevitably a single model to interpret the observations is sought. We recommend that this model be as simple, or smooth, as possible, in order to reduce the temptation to overinterpret the data and to eliminate arbitrary discontinuities in simple layered models. To obtain smooth models, the nonlinear forward pr...

In this paper we develop a fast 3-D electromagnetic (EM) migration method for marine geophysical exploration. The developed migration algorithm is based on downward extrapolation of the observed EM field using a special form of finite-difference equation for the migration field. It allows us to migrate within the sea-bottom formations the EM signals observed by the sea-bottom receivers. The mig...

Author: Pedro Luis Kantek Garcia Navarro Affiliation: CELEPAR Title: AN EVOLUTIONARY APPROACH IN MAGNETOTELLURIC INVERSION Text: Magnetotelluric inversion is the reconstitution of the pattern of underground geolectric conductivities out of an incomplete and noisy set of measurements of the electromagnetic field at various points of the surface, and at various frequencies. In the forward problem...

Tongchuan City, located in Shaanxi Province, northwest China, has limited groundwater resources. Rational planning and exploitation of are crucial to the sustainable development city, for which investigating distribution is premise. Traditional resistivity sounding methods often used detect groundwater; however, these not applicable study area where thick Quaternary loess extensively distribute...

This paper reports an analysis of electromagnetic data from a site occupied on the floor of the Tasman Sea during an Australia-U.S. research program, the Tasman Project of Seafloor Magnetotelluric Exploration. This site (37ø33'S, 155ø58'E, depth 4450 m) is in the central portion of the Tasman Sea, and near both a fossil spreading ridge and the Tasmantid Seamount Chain. The extensive electric an...

We present a method for the solution of 3-D controlled source magnetotelluric (CSAMT) inverse problems. The inverse problem is formulated as the minimization of a Tikhonov parametric functional with a focusing stabilizer. Observed CSAMT apparent resis­ tivities are converted to log-anomalous apparent resistivities, which are linearly connected to anomalous currents via the integral equation. We...