Woods Hole Oceanographic Institution

Dr Rob. L. Evans

»Electrical Lithosphere Beneath the Kaapvaal Craton
»Gulf Of Mexico Gas Seep
»MELT MT Results
»MELT Area Off-Axis Structure
»Wrightsville Beach Geophysics and Hydrology
»Karst Formation off North Carolina
»Review of Shallow Offshore EM Work
»EPR MMR Experiment
»Towed EM System
»Offshore MT and Subduction Systems
»Shallow Porosity Structure on the Continental Shelf
»Oceanic and Continental Mantle Resistivity
»New Jersey EM Survey
»Eel River EM Survey
»Impact of groundwater on EM data
»Electrical structure of Slave Craton
»Report of Shoreline Change Workshop

Rob. L. Evans, Using Controlled Source Electromagnetic Techniques to Map the Shallow Section of Seafloor: From the Coastline to the Edges of the Continental   Slope., Geophysics, pre-print

Many important processes occur within the shallow section of seafloor on the continental shelf and slope, yet conventional geophysical constraints on the physical properties within this critical boundary layer are limited. Some of the key constraints needed involve quantification of fluids within the seafloor which can be provided by electrical methods.

            This paper reviews the application of a towed electromagnetic (EM) system that has been used to map the uppermost 20 m of seafloor in a variety of settings ranging from nearshore regions in water depths of ~10-20 m, across the continental shelf out to water depths of 1300 m. The system is a mapping tool providing areal maps of seafloor resistivity and has been used for a variety of purposes including; sedimentary characterization and facies mapping, evaluation of groundwater discharge, and mapping seafloor mounds in the Gulf of Mexico thought to contain massive gas hydrate.


FILE » Shallow_Section_EM_paper_17443.pdf

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