A remote, multi-sensor station to monitor conditions near the sea floor within the hydrate stability zone

The possibility of designing and developing a remote, multi sensor, monitoring station for long term investigation and research of the near-sea-floor hydrocarbon system within the hydrate stability zone of the northern Gulf of Mexico has been discussed for some years. A program was initiated in 1999 to design and assemble a station which 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. It is planned that an operational station will be installed in at least a thousand meters of water by 2004. The heart of the station will be a net of vertical arrays of sensors. Each array will occupy the lower portion of the water column and a hole bored into the sea floor. Sensors will include hydrophones to record compression waves, thermistors to measure temperature within the water and the sediment, and optic fibers connected to an optical spectrometer to identify and quantify hydrocarbon gases. The lowermost sensor of each array will be a three-component accelerometer pushed into the sediments at the bottom of the hole to record compression and shear waves. Peripheral sensors will include a sea-floor positioning system and an acoustic doppler current profiler. Also, if sufficient electrical power is available, several video systems with pan and tilt capability will be installed. The video images would be posted on a web site in near-to-real time and made available for educational and public outreach purposes.