Geophysical Imaging of Shallow Gas Hydrates Using Electromagnetic Techniques: A Pilot Study in the Gulf Ocean
DOEI Project Funded: 2002
Gas hydrate, an ice-like solid composed of water and natural gas,
can potentially store large quantities of methane, and so its abundance
on the seafloor has important ramifications for the global carbon
budget, for climate, and as a future energy resource. Breakdown
of hydrate has also been implicated in catastrophic failure of
regions of the continental slope, causing landslides and tsunamis.
High-resolution geophysical techniques that image the shallowest
occurrences of gas hydrate hold great potential for providing measures
of the regional methane flux, but large uncertainties remain about
how hydrates are distributed within seafloor sediments, the importance
of localized concentrations of hydrate, and the role that focused
fluid flow plays in controlling these localized concentrations.
We will run a pilot study to test the ability of a new towed electromagnetic system to delineate regions of shallow gas hydrate in the Gulf of Mexico. This survey will be a proof of concept, collecting sample lines in well-surveyed areas. Our results will be used to develop a strategy for obtaining maps of shallow hydrate distributions which can be used to test flux-based models of hydrate formation, and to examine links between shallow hydrates and faults and other conduits that channel methane and fluids to the seafloor.
Originally published: January 1, 2002