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Laying Long Cables

Cable laying is an important task at all of our locations – after all, we're building a cabled seafloor observatory. But it was especially important and challenging at our ODP 1027 location, where we sought to install three 12.5km cables radiating out from the instrument platform to form an equilateral triangle with bottom pressure recorders at each corner. Such an array will be invaluable to researchers studying tsunamis in this region.

To accomplish these cable lays we used ROCLS, ROPOS's Remotely Operated Cable Laying System. ROCLS consists of a rugged aluminum frame that holds detachable cable drums. Individual cables are carefully spooled onto drums. Then, when it is time to deploy, they are fitted onto ROCLS. ROPOS is then attached to ROCLS and the two deployed piggy-back, like tandem parachutists.

If the spool is heavy, it is lowered to the seafloor by the ship's winch. ROPOS is deployed, finds ROCLS on the seafloor and detaches the cable end from the spool for connection to its designated node or platform. Then ROPOS locks onto ROCLS and dispenses cable via a hydraulic motor connected to a chain drive that turns the spool while ROPOS flies over the cable lay route.

ROCLS
Cables spooled onto ROCLS drums aboard the R/V Thompson, 7 September 2009.	Recovery of ROPOS with ROCLS and an empty cable drum.	ROCLS on the seafloor at ODP 1027, fully loaded with a 12.5km extension cable. Here, ROPOS is unfastening the cable end to connect it to our instrument platform.	ROPOS crew member Keith Tamburri and a R/V Thompson crew member prepare a fully-loaded ROCLS spool for deployment, 2 September 2009.

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The 12.5km spools deployed at ODP 1027 were very full and very heavy. Consequently, the ROPOS crew encountered many challenges dealing with them. One of the cables became snarled during deployment, and could not be laid. The spool had to be recovered from the seafloor and the cable now awaits repairs.

Later, a difficult happenstance resulted in ROPOS breaking an arm. After laying 12.5km of cable, ROCLS was set down on the seabed to remove the end connector and attach the bottom pressure recorder. But ROCLS sank too deeply into the soft sediment. ROPOS normally rotates the drum by hand during removal, but this time it would hardly budge. ROPOS operators tried again and again, using the ROPOS arms as levers to inch the drum upward. Finally, a bolt in the right arm snapped, rendering it nearly useless. But the ROPOS crew persevered and eventually managed to complete the installation.

ROPOS Breaks an Arm
The ROPOS team continued using Yang arm even after it broke. Here, the broken claw is lifting the dust cover for the bottom pressure recorder connector, 5 September 2009.	ROCLS sank deeply into the soft sediment on the abyssal plain during deployment of our ODP 1027 bottom pressure recorders. While attempting to rotate the drum by hand, a bolt on the Yang (right) arm snapped, leaving ROPOS with only one functional arm.	ROPOS crew member Dan Cormany worked to repair the broken Yang arm after the dive was completed, 5 September 2009.

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Passing through the Water Column

At over 2.6km, ODP 1027 is our deepest location. This means we spent a lot of time passing through the water column, observing various creatures along the way. Here are photos of some of them. If you can tell us more about any of these organisms, please post a comment below!

Creatures of the Deep
This red jellyfish was captured simultaneously by two different cameras on ROPOS. The left half is from the HD video camera; the right half is from the 3-chip CCD still camera. Observation taken at 1395m, 4 September 2009.	Close-up view of the unusual organism we observed at 1933m during a cable deployment dive at ODP 1027.	This deepsea organism, observed at 1933m depth, seems to resemble flowering Scotch Broom. If you can tell us more about it, please submit a comment below!	A red jellyfish observed at 1395m.
This beautiful jellyfish was observed at a depth of 1220m. We welcome your comments as to the type or other details you may be able to contribute.

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Deployment and Recovery

Whenever ROPOS is deployed, "lemons" are involved. After ROPOS is lowered into the water, lemon-shaped floats are snapped onto the ROPOS umbilical cable to prevent it from snarling the sub during a dive. Of course, during recovery, each "lemon" must be unsnapped and stowed before ROPOS can be lifted onto deck.

Lemons
After ROPOS enters the sea, R/V Thompson crew members snap lemon-shaped floats onto the ROPOS umbilical cable to prevent it from snarling the sub during underwater operations.	When ROPOS returns to the surface, R/V Thompson crew members also help remove the "lemons" from the ROPOS umbilical cable.

(Click images to view slideshow.)

Not all recoveries are equal, though. High seas and gusty winds made an adventure out of our final recovery at ODP 1027.

Stormy Seas
ROPOS crew member Steve Buckley operates the crane during recovery of the sub with ROCLS attached. The task was complicated by high waves and strong winds, 5 September 2009.

Stormy Skies
Storm clouds loomed on the horizon as we recovered ROPOS and prepared to flee ODP 1027 ahead of a developing storm at sea.

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Ocean Drilling Program (ODP) 1027

Juan de Fuca Plate

Ocean Crustal Hydrogeology

Seismograph Network

West Coast "Tsunami-meter"

Ocean Crustal Hydrogeology

Ten boreholes were drilled across the Juan de Fuca Plate between 1991 and 2003 by the Ocean and Integrated Ocean Drilling Programs (ODP/IODP) expressly for the installation of "CORK" (Circulation Obviation Retrofit Kit) hydrologic observatories. These CORKs allow geoscientists to observe changes in sub-surface temperatures and pressures caused by earthquakes, hydrothermal convection and regional plate strain. With live connections to the NEPTUNE Canada network, scientists will gain the ability to monitor stresses and fluid movements in real-time, as they occur.

On September 1, ROPOS attached connectors from our instrument platform to the temperature and pressure instruments on CORK 1026B. Eventually we hope to connect additional CORKs and CORK instruments to our network. More on CORKS.

Seismograph Network

The NEPTUNE Canada Seismograph Network will help seismologists do real-time seismic monitoring and research on the ocean floor. Altogether, we plan to install four broadband seismometers, forming a large footprint spanning our ODP 889, Barkley Canyon, ODP 1027 and Endeavour locations. Three of these broadband seismometers will be installed and connected to our network during the second leg of this summer's installation cruise.

West Coast "Tsunami-meter"

Results of this study will aid in tsunami, storm surge, and earthquake modeling. Highly sensitive bottom pressure recorders (BPRs) with built-in temperature and conductivity sensors will be located at all NEPTUNE Canada node locations. At ODP 1027, the plan calls for a triangular arrangement of 3 bottom pressure recorders, each positioned 12.5km from our instrument platform. Such an arrangement lets scientists make very precise measurements of deep water tsunami wave height, speed and direction of movement.

The 12.5km cables are challenging to lay. When spooled on ROCLS (the ROPOS Remotely Operated Cable Laying System) drums, they weigh over 3.7 metric tons. ROCLS, with spool attached, is lowered to the seafloor using the ship's winch. Then, ROPOS flies to the seafloor, unfastens the cable end from the spool, attaches it to the instrument platform, picks up ROCLS and gradually spools the cable out over the designated path. At the same time, the ship must slowly follow ROPOS, always keeping a careful eye to separation, orientation, track and sea conditions.

ODP 1027 Instrument Platform
An inside view of the ODP1027 instrument platform. The two CORK connectors plug into CORK 1026B, nearby. The connector stowed in the parking station will hook to a seismometer.	Hose and connectors that will enable live data to be gathered from CORK 1026B via the NEPTUNE Canada network.	Connection ports on the ODP 1027 instrument platform. Seabird conductivity-temperature-pressure gauge can also be seen.

On the Deck
Crews of the R/V Thompson and ROPOS work together to move a fully loaded ROCLS (3.7 metric tons) into position for deployment by crane to the seafloor.	Canadian Scientific Submersible Facility general manager Keith Shepherd prepares the ROCLS cable-laying frame for lowering to the seafloor by winch.	R/V Thompson crew used the ship winch to move the ODP 1027 instrument platform into position on deck prior to deployment by ROPOS, 29 August 2009.

On the Seafloor
ODP 1027 instrument platform during installation.	ROPOS plugs a connector into the CORK 1026B pressure instrument, 1 September 2009.	The ODP 1026B CORK wellhead from above. Two instruments, for monitoring temperatures and pressures within the earth's crust, are connected to the NEPTUNE Canada network. The top of this wellhead was inhabited by an octopus.	ROPOS rigs the extension cable connecting the ODP 1027 node to the instrument platform 3.5km away.

Local Sealife
This octopus seemed unintimidated by ROPOS, even while we removed the dust cover to the temperature instrument port and plugged in the connector.	This kind of sea cucumber is called a "Sea Pig".	A kind of sea cucumber (Scotoplanes sp.) we found crawling near ODP 1027.	Detailed view of a sea pen (Umbellula sp.) found at the ODP 1027 site.
A sea pen (Umbellula sp.) found at the ODP 1027 site.