Cabled Array

Cabled Array. A permanent, high-power, and high-bandwidth submarine observatory system located on the Juan de Fuca Plate in the Northeast Pacific Ocean. It forms the cabled component of the Ocean Observatories Initiative, providing real-time, continuous data from the seafloor and throughout the water column to shore-based researchers. The array represents a transformative platform for conducting long-term, interactive experiments in marine geology, physical oceanography, and ecosystem dynamics.

Overview

The facility is a pioneering undersea observatory that delivers unprecedented electrical power and Internet connectivity to a suite of scientific instruments deployed across diverse oceanographic environments. Funded primarily by the National Science Foundation and operated by the University of Washington, it enables scientists to monitor complex earth-ocean systems in real time. This continuous data stream supports investigations into phenomena such as plate tectonics, ocean acidification, and hydrothermal vent ecosystems, moving beyond traditional, episodic research vessel-based sampling.

Design and Infrastructure

The core infrastructure consists of two high-voltage submarine communications cables, laid from a shore station in Pacific City, Oregon, that traverse approximately 500 kilometers to primary nodes on the ocean floor. These primary nodes, situated at the Endurance Array offshore site and on the Axial Seamount, function as underwater electrical outlets and network switches, distributing power and bandwidth. From these nodes, secondary infrastructure, including backbone cables and junction boxes, extends the network to instrument platforms hosting hundreds of sensors. Key instrument types include seismometers, CTD profilers, mass spectrometers, hydrophones, and high-definition video cameras, all designed for long-term deployment in harsh deep-sea conditions.

Scientific Applications

The array facilitates multidisciplinary research across the earth sciences. At the Axial Seamount, an active submarine volcano, instruments monitor magma chamber inflation, microearthquake swarms, and eruptions, providing a detailed understanding of mid-ocean ridge processes. Biologists use the system to study the unique chemosynthetic ecosystems at hydrothermal vent fields like ASGARD and International District Vent Field without disruptive human presence. Oceanographers analyze data from moored profilers and ADCPs to study ocean circulation, carbon cycle fluxes, and the effects of climate change on oxygen minimum zones. The real-time capability also allows for rapid response to events like earthquakes or harmful algal blooms.

Data and Observations

All data collected by the observatory are transmitted in real time to the shore station and then to the Ocean Observatories Initiative Data Portal, where they are made publicly available. This open data policy has yielded a vast, continuous, and multi-parameter dataset encompassing physical, chemical, geological, and biological variables. Notable observations include the documented eruption of the Axial Seamount in 2015, the tracking of ocean soundscape variations, and long-term time-series of methane flux from seafloor seeps. The data are integral to models improving forecasts for tsunamis, climate model projections, and understanding biodiversity in the deep sea.

Operational History

The concept evolved from earlier seafloor observatory experiments like VENUS and NEPTUNE Canada. Major construction, involving the RV Thompson and RV Roger Revelle, occurred between 2011 and 2014, with the system achieving full operational capability in 2015. The first major scientific event captured was the 2015 eruption at Axial Seamount, validating the observatory's design. Regular maintenance and instrument turnover operations are conducted annually by University of Washington teams using ROVs such as ROV Jason from vessels like the RV Atlantis. The array is designed for a 25-year lifespan, with ongoing upgrades to its sensor suites and network capacity to address emerging scientific questions.

Category:Oceanographic instrumentation Category:Research infrastructure Category:Undersea cables