s, 28, 719–722. Commer, M., and G. Newman, 2008a, New advances in three-dimensional controlled source electromagnetic inversion: Geophysical Journal International, 172, no. 2, 513–535, doi:10.1111/j.1365-246X.2007.03663.x. ———, 2008b, Optimal conductivity reconstruction using three-dimensional joint and model-based inversion for controlled-source and magnetotelluric data: 78th Annual Internatio...

A new type of electromagnetic (EM) receiver has been developed by integrating four capacitive electrodes and a triaxial induction coil with an advanced data logger for tunnel exploration. The new EM receiver can conduct EM observations in tunnels, which is one of the principal goals of surface-tunnel-borehole EM detection for deep ore deposit mapping. The use of capacitive electrodes enables us...

[1] Constraints on bulk conductivity from magnetotelluric measurements and petrological analyses of late Quaternary peridotite xenoliths from the southern Sierra Nevada allow evaluation of models commonly used to relate electrical conductivity to the physical and chemical state of the upper mantle. In these models, two conductive melts (basalt and sulfide) are embedded in a resistive matrix. Bo...

EarthScope is the United States Earth Science Pro gram to explore the structure and evolution of the North American continent and understand processes control ling earthquakes and volcanoes. A major part of the EarthScope project is the Transportable Array which will be deployed over the next decade over the entire continental United States. This Transportable Array will provide an unparalleled...

[1] We present the first use at a mid-ocean ridge of a recently developed broadband marine magnetotelluric (MT) instrument. The extended high frequency performance of the instrument allows resolution of electrical resistivity structure at shallower depths than traditional marine MT sensors. Our two-dimensional inversion model from data collected at four MT sites on the East Pacific Rise (EPR) a...

In recent papers Caldwell, Bibby and Brown (2002, 2003) (hereafter referred to as CBB) have introduced a new and elegant method for analysing magnetotelluric (MT) data which can be applied directly to galvanically distorted data in a regional conductivity structure of any dimension. It is therefore more general and direct than previous methods (e.g. Bahr, 1988; Groom and Bailey, 1989; Smith, 19...