[1] The magnetotelluric dataset collected on the San Andreas Fault at Parkfield has been re-analyzed using superior inversion algorithms that have been developed in recent years. A combination of constrained inversion, forward modeling and synthetic inversion studies are used, and show that at the SAFOD site, the low resistivity fault zone extends to a depth of 2–3 km. An extended zone of low r...

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...

In the magnetotelluric (MT) method, the analysis of geoelectric dimensionality has acquired special importance in the last years, because numerical codes have made it possible to model and invert data using either one-dimensional (1D), two-dimensional (2D) or three-dimensional (3D) approaches. We present a FORTRAN code termed WALDIM to perform the dimensionality analysis of a set of MT data, ac...

A new approach to the problem of direction and distance ®nding of magnetospheric ULF oscillations is described. It is based on additional information about the structure of geoelectromagnetic ®eld at the Earth's surface which is contained in the known relations of the theory of magnetovariation and magnetotelluric sounding. This allows us to widen the range of diagnostic tools by using observat...

The Ries Crater was formed about 12 million years ago, 120 km northwest of Munich in the district of Donau-Ries. The crater is estimated to have had a diameter of approximately 24 kilometers. In this report we discuss the preand post-impact structure of the crater site, and in particular try to investigate whether or not the Ries Crater shows evidence of structural uplift, a characteristic of m...