SUPPORT OF GULF OF MEXICO HYDRATE RESEARCH CONSORTIUM: ACTIVITIES TO SUPPORT ESTABLISHMENT OF A SEA FLOOR MONITORING STATION PROJECT

Abstract

A Consortium, designed to assemble leaders in gas hydrates research, has been established at the University of Mississippi's Center for Marine Resources and Environmental Technology, CMRET. The primary objective of the group is to design and emplace a remote monitoring station on the sea floor in the northern Gulf of Mexico by the year 2005, in an area where gas hydrates are known to be present at, or just below, the sea floor. This mission necessitates assembling a station that will monitor physical and chemical parameters of the sea water and sea floor sediments on a more-or-less continuous basis over an extended period of time. Development of the station allows for the possibility of expanding its capabilities to include biological monitoring, as a means of assessing environmental health. Establishment of the Consortium has already succeeded in fulfilling the critical need to coordinate activities, avoid redundancies and communicate effectively among researchers in this relatively new research arena. Complementary expertise, both scientific and technical, has been assembled to innovate research methods and construct necessary instrumentation. As funding for this project, scheduled to commence December 1, 2002, had only been in place for less than half of the reporting period, project progress has been less than for other reporting periods. Nevertheless, significant progress has been made and several cruises are planned for the summer/fall of 2003 to test equipment, techniques and compatibility of systems. En route to reaching the primary goal of the Consortium, the establishment of a monitoring station on the sea floor, the following achievements have been made: (1) Progress on the vertical line array (VLA) of sensors: Software and hardware upgrades to the data logger for the prototype vertical line array, including enhanced programmable gains, increased sampling rates, improved surface communications, Cabling upgrade to allow installation of positioning sensors, Incorporation of capability to map the bottom location of the VLA, Improvements in timing issues for data recording. (2) Sea Floor Probe: The Sea Floor Probe and its delivery system, the Multipurpose sled have been completed; The probe has been modified to penetrate the <1m blanket of hemipelagic ooze at the water/sea floor interface to provide the necessary coupling of the accelerometer with the denser underlying sediments. (3) Electromagnetic bubble detector and counter: Initial tests performed with standard conductivity sensors detected nonconductive objects as small as .6mm, a very encouraging result, Components for the prototype are being assembled, including a dedicated microcomputer to control power, readout and logging of the data, all at an acceptable speed. (4) Acoustic Systems for Monitoring Gas Hydrates: Video recordings of bubbles emitted from a seep in Mississippi Canyon have been made from a submersible dive and the bubbles analyzed with respect to their size, number, and rise rate; these measurements will be used to determine the parameters to build the system capable of measuring gas escaping at the site of the monitoring station; A scattering system and bubble-producing device, being assembled at USM, will be tested in the next two months, and the results compared to a physical scattering model. (5) Mid-Infrared Sensor for Continuous Methane Monitoring: Progress has been made toward minimizing system maintenance through increased capacity and operational longevity, Miniaturization of many components of the sensor systems has been completed, A software package has been designed especially for the MIR sensor data evaluation, Custom electronics have been developed that reduce power consumption and, therefore, increase the length of time the system can remain operational. (6) Seismo-acoustic characterization of sea floor properties and processes at the hydrate monitoring station. (7) Adaptation of the acoustic-logging device, developed as part of the European Union-funded research project, Sub-Gate, for monitoring temporal variations in seabed acoustic responses has commenced. Electronics as well as hardware are undergoing development specific to this DOE project.