OOI Regional Cabled Array Demonstrates Multi-Span Fiber Sensing
The Nokia Bell Labs system overcomes signal loss at optical repeaters by using high-loss loopback couplers, extending sensing across the full length of submarine fiber optic cables—far beyond previous limits of about 65-95 km .
Two RCA cables extend offshore from Pacific City, Oregon: the northern cable (~480 km) reaches Axial Seamount, while the southern cable (~350 km) crosses the continental shelf onto the Juan de Fuca Plate .
"This experiment shows that we can transform existing subsea cables into powerful, large-scale sensing systems," said William Wilcock, professor of Oceanography at the UW. "It's a powerful new tool to observe ocean and Earth processes continuously over hundreds to thousands of kilometers" .
The system enables detection of earthquakes, ocean waves, and marine mammals such as whales, offering potential for improved offshore earthquake monitoring and early warning in the Pacific Northwest .
