Crustal fluids exist near fault zones, but their relation to the processes that generate earthquakes, including slow-slip events, is unclear. Fault-zone fluids are characterized by low electrical resistivity. Here we investigate the time-dependent crustal resistivity in the rupture area of the 1999 Mw 7.6 Izmit earthquake using electromagnetic data acquired at four sites before and after the ea...

Magnetotelluric (MT) studies can map subsurface resistivity structure and have located zones of low resistivity (high conductivity) within major strike-slip fault zones worldwide which have been interpreted as regions of elevated fluid content. This study describes MT data from the eastern part of the North Anatolian and the East Anatolian Fault Systems (NAFS and EAFS) and presents the results ...

A stochastic Bayesian approach for combining well logs and geophysical surveys for enhancing subsurface characterization is presented. The main challenge we face is in creating the bridge to link between ambiguously related geophysical surveys and well data. The second challenge is imposed by the disparity between the scale of the geophysical survey and the scale of the well logs. Our approach ...

An automatic inverse method has been developed for generating layered earth models from electrical sounding data. The models have the minimum number of layers required to fit a resistivity sounding curve or a combined resistivity and induced polarization sounding. The ground is modeled using a very large number of thin layers to accommodate arbitrary variations. The properties of the layers are...

we use high-resolution electrical resistivity imaging to delineate the geometry of the landslide and discontinuity surface between slide mass and bedrock in roudbar region, ghazvin-rasht-anzali railway (the tunnel no. 2 at km. 108+825). the roudbar region characterized by high geological hazard and shows a complete panorama of mass movements. in this area, different landslide types predisposed ...

Koyna region is well-known for its triggered seismic activities since the hazardous earthquake of M = 6.3 occurred around the Koyna reservoir on 10 December 1967. Understanding the shallow distribution of resistivity pattern in such a seismically critical area is vital for mapping faults, fractures and lineaments. However, deducing true resistivity distribution from the apparent resistivity dat...