Canada: Neptune Completes Investigation of Their 800-km Cabled Network Along Northern Juan de Fuca Plate

NEPTUNE Canada navigated an impressive installation and maintenance cruise in the northeast Pacific Ocean.

Diving down to the seafloor to investigate their 800-km cabled network observatory along the northern Juan de Fuca plate, they tended to their technically-advanced instruments and witnessed some of the amazing marine life dwelling off the coast of Vancouver Island, British Columbia.

 The Journey

Aboard the R/V Thomas G. Thompson (University of Washington), they completed 33 dives at all 5 active node locations. Their route was

•  ODP 1027 (2660 m depth)
• Endeavour (2300 m depth)
• ODP 889 (1260 m depth)
• Barkley Canyon (396 – 981 m depth)
• Folger Passage (100 m depth)

Fortuitously, smooth seas and astute judgement hailed the ship around for a second pass, returning it to Barkley Canyon, Endeavour and ODP 889.

 The Highlights

In their 21 days at sea, they

•  Installed 15 instruments;
• Redeployed 4 instrument platforms and 11 instruments;
• Recovered 2 instrument platforms, 26 instruments, Wally the Crawler (carries an additional 7 instruments), and 9 km of electric-optic cable;
• Repaired IODP CORK U1364A and successfully downloaded data;
• Surveyed areas to lay down new cable during their next cruise.

On top of all this maintenance, they gathered 117 samples during 21 of the 33 dives and at nearly every visited location. When their science crew arrived at the Esquimalt Graving dock, they greeted them with a car full of coolers! The principal investigators and their research teams will analyze the samples, which included:

•  Tubeworms
• 4 scoop samples
• 20 water samples
• 28 Niskin bottles
• 65 push-core sediment samples

One of the major objectives of the cruise was to investigate the power outage at Barkley Canyon that occurred on February 18, 2011. Site inspection showed instrument and cable damage at Barkley Upper Slope and Barkley Benthic Pod 2, which may have been caused by a trawl hit. All equipment was accounted for and the end of the main extension cable was recovered, sealed, and will be re-terminated. Actual repair is planned for 2012. The 2 instrument platforms and a number of instruments were brought back for further repair. At this point, they stand to lose over a year of unique and valuable data from this benthic environment. Furthermore, they were forced to delay deploying the Vertical Profiler System (VPS), which consists of a seafloor platform and a motorized tethered float that serves as a host to a collection of instruments for monitoring processes in the water column.

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Source: neptunecanada, August 01, 2011