Electromagnetic surveying of seafloor mounds in the northern Gulf of Mexico

Seafloor controlled source electromagnetic data, probing the uppermost 30 m of seafloor sediments, have been collected with a towed magnetic dipole–dipole system across two seafloor mounds at approximately 1300 m water depth in the northern Gulf of Mexico. One of these mounds was the focus of a rece...

Full description

Saved in:
Bibliographic Details
Published in:Marine and petroleum geology 2008-11, Vol.25 (9), p.960-968
Main Authors: Ellis, M., Evans, R.L., Hutchinson, D., Hart, P., Gardner, J., Hagen, R.
Format: Article
Language:English
Subjects:
Electromagnetics
Gas hydrate
Gulf of Mexico
Marine
Ocean drilling
Resistivity
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Seafloor controlled source electromagnetic data, probing the uppermost 30 m of seafloor sediments, have been collected with a towed magnetic dipole–dipole system across two seafloor mounds at approximately 1300 m water depth in the northern Gulf of Mexico. One of these mounds was the focus of a recent gas hydrate research drilling program. Rather than the highly resistive response expected of massive gas hydrate within the confines of the mounds, the EM data are dominated by the effects of raised temperatures and pore fluid salinities that result in an electrically conductive seafloor. This structure suggests that fluid advection towards the seafloor is taking place beneath both mounds. Similar responses are seen at discrete locations away from the mounds in areas that might be associated with faults, further suggesting substantial shallow fluid circulation. Raised temperatures and salinities may inhibit gas hydrate formation at depth as has been suggested at other similar locations in the Gulf of Mexico.
ISSN:0264-8172
1873-4073
DOI:10.1016/j.marpetgeo.2007.12.006