Backgrounder: Neptune Canada Wires Subsea Volcanic Region
Starting Sept. 12, NEPTUNE Canada will install the fifth and most challenging portion of its cabled ocean observatory—2.3 km below the ocean surface at Endeavour Ridge. The NEPTUNE Canada team departs from Esquimalt on a month-long journey 300 km offshore, after loading the University of Washington’s research vessel T.G.Thompson with instrumentation, cables, and specialized installation equipment, including the remotely operated vehicle, ROPOS.
Endeavour Ridge is NEPTUNE Canada’s most remote site, where new volcanic seafloor is being created at the spreading boundary between the Juan de Fuca and Pacific tectonic plates. Multiple volcanic eruptions per decade, and more than 3,000 earthquakes per year occur in this region.
A network of seis¬mometers at Endeavour will provide high-resolution information on tectonic processes at this rifting zone between the two plates. Instrumented buoys extending 250 metres above the seafloor will document ocean currents and chemical fluxes. Scientists will also observe the unique deep-sea “black smoker” ecosystems that flourish at this site.
NEPTUNE Canada’s journey to Endeavour begins with two days at the Barkley Canyon node site where “Wally,” the world’s first Internet-operated deep-sea crawler—used to study gas hydrate deposits—will be replaced with “Wally II.” The team will also install a world leading vertical profiler system, which carries instruments from the seafloor to the ocean surface.
Endeavour presents many technical challenges. A 13-tonne node, which provides power and communications, was installed in September 2009. It’s in a location twice the distance from the ridge than originally planned due to the lack of a large enough landing area. As a result, a complete cable redesign was required.
Once at Endeavour, seafloor surveys will be conducted to determine the best route for three 6-km cable extensions that will connect the node to the vent study areas. These cables need to be laid with great care to avoid crevasses, sharp rocks and hot vents. Protective mats will be placed under the cables in areas where glass-like rock is present. Once the cables are successfully laid, the ROPOS submersible will initially connect 18 instruments, with more to come in future years.
The expedition is led by Dr. Mairi Best, NEPTUNE Canada’s associate director (science), and Lucie Pautet, NEPTUNE Canada’s associate director (engineering). Live video, twitter feeds, and blogs will all be streaming from the ship. Join scientists in virtual participation with the cruise (neptunecanada.ca).
Weather at sea can change schedules and plans but if all goes well, the Thompson will return to Victoria on Oct. 11.
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