The next major milestone in construction of the Ocean Observatories Initiative (OOI) program’s Regional Scale Nodes (RSN) cabled network component is scheduled for completion this summer with the installation of the primary nodes, the seven main connection points on the network for power and communications.
The OOI regional cabled observatory, located in the northeast Pacific Ocean, will establish an interactive network of ocean observing sensors, instruments, and moorings connected by a total of 900 kilometers (~ 560 miles) of electro-optical cable. The OOI team is scheduled to begin installing the first node on July 9 and, based on good weather and successful testing results, will complete installation of the last node on Aug. 16. A Notice to Mariners has been issued to notify all marine users of the upcoming operations off the Coast of Oregon.
The RSN cables extend to two main study sites: Hydrate Ridge, located at the base of the Oregon continental margin approximately 120 kilometers (~75 miles) southwest of Pacific City, Ore., and Axial Seamount, located 500 kilometers (~ 310 miles) west on the Juan de Fuca Ridge (See graphic of site map). The RSN cables also will serve the cabled moorings of the OOI’s Coastal Scale Nodes Oregon Line at the Endurance Array site (Nodes 1C and 1D in figure). Two primary nodes will be installed at Hydrate Ridge, two at Axial Seamount, two on the Endurance Line, and one in the middle of the Juan de Fuca plate, a placeholder with minimal internal electronics that will be available for future network expansion.
Once connected to the cable, each primary node installed will provide two-way communication between land and sea and will supply instrument arrays with up to 10 gigabits per second of communications bandwidth and 8 kilowatts of power. Data will be collected by instruments from the sea surface to the seafloor, transmitted by cable, and publicly available onshore in near-real time via the Internet.
The RSN will be the first U.S. regional cabled observatory. The infrastructure is designed to operate continuously for 25 years and is scheduled to be operational in 2014.
John R. Delaney, Director and Principal Investigator of the OOI Regional Scale Nodes and Professor of Oceanography at the University of Washington, explained that cabled ocean observatories allow for unprecedented real-time interactive and adaptive investigations of a range of physical, chemical, geological and biological processes occurring in the ocean over a wide range of space and time scales.
“The OOI regional cabled network will address two major themes: 1) the provision of power and bandwidth to empower and develop a host of exciting new and rapidly developing technologies; and 2) a sustained, long-term and distributed virtual human ‘telepresence’ throughout the ocean for decades,” Delaney said.
For example, scientists will be able to collect around-the-clock data from the seafloor to the sea surface, including measurements on large-scale currents and biological productivity, hydrothermal vents and undersea volcanoes, cycling of carbon in the oceans, and seismic activity that can trigger earthquakes and tsunamis.
The OOI, a National Science Foundation-funded program, is managed and coordinated by the OOI Program Management Office at the Consortium for Ocean Leadership in Washington, D.C. The University of Washington (UW) is leading the design and construction of the OOI RSN cabled component. The primary node installation team includes personnel from the OOI program at UW and Ocean Leadership, primary infrastructure contractor L-3 MariPro, subcontractor TE SubCom and the Oregon Fishermen’s Cable Committee. Two protected species visual observers also will be onboard the installation vessel, the Cable Ship TE SubCom Dependable.
The undersea cable was laid in segments last summer and was connected to the OOI shore station in Pacific City. Click here to read more and see photos of that part of Cable Installation. This summer, in a delicate ballet of cable retrieval, cutting, testing, on-deck splicing, and computerized positioning calculations, the primary nodes will be connected to the cable and then deployed to their precisely identified locations on the seafloor. Using a remotely operated vehicle, cables in the shallower waters of the continental shelf will be buried to protect the system from bottom fishing activities.
“The Primary Node installation will be a unique operation, a precision act requiring constant and simultaneous monitoring of the cable tension and node positioning,” said Cecile Durand, the OOI Marine Maintenance Manager at the University of Washington. “L3-Maripro, TE Subcom, UW and Ocean Leadership have worked together for several months to evaluate a number of installation scenarios and are ready for the challenges ahead. We look forward to successful operations this summer and are already preparing for the next phase.”
OOI personnel at the shore station in Pacific City will be actively involved in the node installation. They will closely monitor L3-MariPro’s activities while the system is powered on and off during the ship-based tests and deployments.
Other work scheduled for this summer includes replacing a segment of cable laid in 2011 on the flank of Axial Seamount. Cable inspection operations during the VISIONS ’11 expedition in August 2011 revealed that segment 7 had been damaged when laid over a previously undiscovered area of active hydrothermal venting associated with the Axial underwater volcano. An alternative, safer cable route was identified for this summer’s installation.
In preparation for the primary node deployment this summer, a dockside rigging test took place aboard the CS Dependable on April 17 and 18, 2012 at Swan Island in Portland, Ore. Click here to read more on the recent Dockside Primary Node Rigging Test and here to see Detailed RSN Instrument Tables.
To track the RSN primary node installation activities, visit the RSN Blog here.