NeMONet: a near real-time deep ocean observatory

The New Millennium Observatory Network (NeMONet) system was deployed, by NOAA/PMEL, in the NE Pacific along the Juan de Fuca Ridge in September 1999. This system is one of the first remote underwater, near real-time observatories implemented with the capability of bringing scientific data directly from ocean depths to the desktop. Located approximately 300 miles offshore and 1500 meters underwater, the assemblage was positioned adjacent to a hydrothermal vent near an underwater volcano with the ability to collect and transmit near real-time images of vent activity and temperature measurements at specific intervals for approximately one year. The basic design goal was proof of concept and to accommodate a broad spectrum of scientific applications ranging from chemical to biological to geographical data collection in future deployments. The NeMONet consists of a sub-sea unit that was strategically positioned on the seafloor with a Remotely Operated Vehicle (ROV) and a taut-line surface mooring that was deployed nearby. Communication from the seafloor to the surface is made possible by using commercial acoustic modems and from the buoy to shore via a geostationary satellite. All buoy and sub-sea communications are handled by carefully programmed controllers with hardware designed for low power and data compression to fit the narrow bandwidth of the transmission paths. The images and data are placed on the Web shortly after being received ashore. The successful operation of the NeMONet system with the first deployment has given encouragement to develop a follow-on system and make plans for future enhancements to the observatory