Research | GoM Hydrate
Marine Electromagnetic Methods for Gas Hydrate Characterization
EM Lab Personnel:
Karen Weitemeyer, Steven Constable
Building on our pilot study over Hydrate Ridge, this project surveyed four areas in the Gulf of Mexico
(MC 118, GC 955, WR 313, and AC 818) using much improved CSEM methodology. First proposed in mid-2005, this survey has had a long gestation for various reasons, but finally went ahead in October 2008.
Funding for this work came from DoE/NETL, MMS, UC Shipfunds, Chevron, ExxonMobil, WesternGeco,
EMGS, Fugro, CGG/Veritas, Statoil, and Shell.
Click here to download the cruise report for this work, PDF
Click here to download the updated proposal for this work, PDF
What is marine CSEM?
What are gas hydrates?
Real-time (at the time) Cruise Updates:
Steve's daily Log from
the R.V. Roger Revelle
images from the HiSeasNet
cameras and a Google map of the R.V. Revelle's current
Latest Movie from the HiSeasNet IQEye Deck Camera
Selected Images (most recent at the top):
October 23, 2008. Here's a
map of the ship's track around all five survey locations.
October 22, 2008. Steve Reese, John Souders, Arnold Orange,
Chris Armerding, and Karen Weiteyer looking appropriately bored as we run the sixth tow line over the
MC118 survey area. Arnie is controlling the winch.
October 20, 2008. The main deck during the multibeam survey, when all the
receivers are on board.
Some of the things we've been talking about have been labeled. The electrode arms are stored upright in
plastic bins on the port side of the ship to the right of the photographer. The famous barracudas
are stored under cover.
October 19, 2008. Paying out line between Vulcan and the SUESI
antenna, just before SUESI's deployment this afternoon. Nice weather!
October 18, 2008. A snapshot sample of
data (one frequency from one pass from one site from one survey - 0.01% of the data collected
so far) that Steve was bragging about. (This image has been modified from that originally posted - we had a gain error in the processing.)
October 17, 2008. The
cruise logo! This cruise almost happened in the summer of 2007
but was delayed at the last minute by bureaucratic matters,
hence the modified logo.
October 16, 2008. Here
are two photos of SUESI #1 (Scripps Undersea EM Source Instrument).
As discussed in Steve's diary, SUESI
#1 is a happy transmitter and has been performing well. The
cruise has now completed two hydrate surveys (AC818 and WR313.).
October 14, 2008, Part II. They've
arrived at Walker Ridge 313 and deployments are to commence
shortly. The second map shows the predicted paths for two tropical
depressions and Hurricane Omar. Looks like the remainder of
the Hydrate cruise should be okay, but I wouldn't want to be
in Puerto Rico.
October 14, 2008, Part I. Here
are two images Steve emailed from the ship. The first image
is the towed 3 component EM receiver "Vulcan" being
deployed through the A-frame. The second image is a 3 component
seafloor receiver being recovered. The long yellow arms contain
silver-silver chloride electrodes at their ends, and the horizontal
electric field is recorded as the potential difference between
pairs of the arms. The shorter vertical pole is for measuring
the vertical electric field. The short blue tubes attached
to the instrument frame contain induction coil magnetometers
that record the time varying magnetic field.
October 13, 2008. Looks
like the survey at AC 818 is finished. SUESI is back on deck
and the team is recovering the transmitter antenna cable,
then they'll have to pull Vulcan out of the water.
October 12, 2008. Nighttime
operations with SUESI being deployed through the A-frame. Read
Steve's cruise log diary to learn more. Click
here to watch a movie sequence of the SUESI and Vulcan deployment.
October 11, 2008. Compare
this to October 8––all the receivers have been
deployed to the seafloor. Click here to watch a 24 hour sequence
of images from this HiSeasNet camera.
October 10, 2008. The
Revelle has arrived at Alaminos Canyon 818.
October 9, 2008. Sunrise
and a water spout photos, both taken this morning by Alex James.
October 8, 2008. R/V Revelle in transit with a full deck of
transmitter, the Vulcan towed receiver
and stacks of concrete
anchors. Steve Constable and John Souders
are on deck testing the EM transmitter SUESI.