« Events

Speaker: Steven Constable, Professor of Geophysics, Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography

Host: Eric Attias

Title: Mixing electricity and water: The world of marine electromagnetic methods

Abstract: Electrical conductivity can be used to estimate rock porosity, tell freshwater from saltwater, oil from water, melt from solid rock, ice or gas hydrate content, and even temperature. Electromagnetic methods were developed on land in the 1960’s and taken into the marine environment soon after, but marine EM remained an academic niche until commercialization around the turn of the century provided resources to advance instrumentation and software, pushing marine EM methods into the mainstream. Now, any application of EM methods on land can, and has, been taken offshore. Plate boundary studies show the distribution and extent of melting at ridges and fluids in subduction systems. Gas hydrate on the continental margins can be quantified in ways nearly impossible with seismic methods. EM methods are uniquely positioned to study offshore groundwater, and could play an important role in geotechnical studies such as those necessary for offshore wind farm infrastructure.