Final preparations are underway for deployment and testing of the Gas Hydrates Sea Floor Observatory in Mississippi Canyon, northern Gulf of Mexico (GOM), spring, 2005. The project is managed by the GOM Hydrates Research Consortium which consists of research teams from academia, industry and government. The overall program is supported by the DOI/MMS, the DOE/NETL and the NOAA/NURP. Primary objectives of the observatory project are to provide long term monitoring of interactions between the near-seabed hydrocarbon system and the hydrate stability zone section. Areas of particular focus are the formation and dissociation of hydrates, transiting pore fluids, and possible vertical migration of the discontinuity at the base of the hydrate stability zone. Acquired data should enable the formulation of viable models for a better understanding of gas hydrates, transiting hydrocarbons and relative interactions within and in proximity to the hydrate stability zone. The models are anticipated to provide a better understanding of relationships between hydrates, pore fluids, and related phenomena including sea floor stability, energy resource potential, and global climate change.
The Gulf of Mexico Gas Hydrates Research Consortium is in the final stage of preparation for the installation of a multisensor sea floor observatory for more or less continuous, longterm monitoring of the hydrocarbon system within the natural gas hydrate stability zone (HSZ) in the northern Gulf of Mexico. The consortium consists of researchers from academia, industry, and government agencies and relies on support from the Department of Interior's Minerals Management Services (DOI/MMS), the Department of Energy's National Energy Technology Laboratory (DOE/NETL), and the National Oceanic and Atmospheric Administration's National Undersea Research Program (NOAA/NURP). Each of the cosponsoring agencies has its own interest in gas hydrates. For MMS, the link between the dissociation of gas hydrates into their component gases and freshwater presents a seafloor stability concern; for DOE/NETL, the tremendous volumes of gas believed to be sequestered as gas hydrates and the natural gas trapped beneath the gas hydrate stability zone represent a vast potential energy resource; for NOAA/NURP, the dissociation of gas hydrates and the resultant release of significant volumes of free gas to the water-column and, eventually, the atmosphere, presents a climatic concern with implications that include global-warming and sea level rise.
Over the past six years, the Consortium has been involved in the design and development of a variety of tools and sensors appropriate for the monitoring task, and in conducting research cruises with both surface and submarine vessels for the purpose of selecting an appropriate site for the Observatory. Principal citing criteria included the presence of outcropping hydrates and hydrocarbon gases venting to the water column, water depths less than 1000m, and location in an open (unleased) block approved by the MMS. The final site selection was Mississippi Canyon, Block 118 (Figure 1).
Figure 1. Mississippi Canyon Federal Lease Block 118, northern Gulf of Mexico. (Available in full paper)
The observatory will employ multi-sensor arrays to provide more-or-less continuous monitoring of hydrographic, geophysical, geological and bio-geochemical characteristics at, above, and below the sea floor.