Design of the OOI Regional Cabled Array northern and southern lines


Hi Tom,

The southern line of the Regional Cabled Array, which connects to the Oregon Offshore and Shelf sites of the Endurance Array, starts at the same shore station as the northern line in Pacific City, OR. The northern line runs west across the Juan de Fuca Plate to Axial Seamount, sending power and delivering real-time data from the volcanic caldera and instruments at the base of the seamount. The Southern line extends south to connect to a site at the base of the Continental Slope (2900 meters water depth), then runs back upslope to Southern Hydrate Ridge, where instruments record data on the methane seeps and chemosynthetic communities, and then further east to the Oregon Offshore site (which has two cabled water column profiler moorings and seafloor instrumentation at 600 m) and finally the Oregon Shelf site (which hosts a bioacoustic sonar platform, cameras, and other seafloor sensors at 80 m to complement the uncabled surface moorings and glider deployments). The northern and southern lines are separate in terms of primary power and bandwidth, but both are monitored and powered from the Pacific City shore station and maintained by the University of Washington.

Please let us know if you have any other questions about the design or operation of the OOI Regional Cabled Array.

Mike Vardaro

Research Scientist
University of Washington, School of Oceanography
1503 NE Boat Street, Box 357940
Seattle, WA 98195-7940

From: on behalf of Tom Qiu
Date: Tuesday, November 8, 2022 at 1:34 PM
To: “”
Subject: [OOI] question about endurance backbone cable layout


I am curious why Endurange array cable has a big loop?


Chuantao Qiu 邱传涛 P.L.Eng | Project Engineer

Ocean Networks Canada | T (250)-721-6135 |
University of Victoria Marine Technology Centre
#206-9865 West Saanich Road, North Saanich, BC V8L 5Y8

Thank you Mike,
my question is why the cable does not go to Node site directly, it looks shorter.
there must be a specific reason that backbone cable runs from shore station to offshore and come back to inshore.

Yes, the design went through a process of conceptual, preliminary, and final design review, and there were a number of reasons for eventually having it head offshore first, then curve back. We’re gathering up the specifics on why it looks the way it does and should get the full answer back to you soon.

Hi Tom, Thanks for your inquiry. There were 275 scientists involved in 16 proposals to form the foundational sites for the Regional Cabled Array. During the planning process, the sites were provided to a telecommunications evaluation team composed of leads in submarine cabled systems. We provided them the sites with no restriction on the footprint. They came back with the two cabled design as it posed the lowest risk and the greatest opportunity for expansion. The loop to the south, running due west off shore to the abyssal plain and then south is to avoid cable lays parallel to the margin, which increases significant risk of breakage during seismic events and also to allow for the possibility of an extension of the array to the Blanco Transform fault in the future.

Thank you very much Prof. Kelley for the clearly explanation.