Innovative Use of Fiber Optic Cables Enhances Earthquake Detection

Researchers at the University of Washington have made significant strides in earthquake detection by utilizing fiber optic cables previously employed for telecommunications to monitor offshore faults. This innovative technique, known as Distributed Acoustic Sensing (DAS), allows scientists to analyze vibrations on the ocean floor and improve early warning systems for earthquakes. The study, published on February 28, 2023, in the *Seismological Research Letters*, showcases the potential of DAS technology in regions like the Cascadia Subduction Zone, where the Juan de Fuca plate interacts with the North American plate, posing a substantial seismic threat to coastal communities.

The research team, led by Marine Denolle, an associate professor in the Earth and Space Sciences Department at the University of Washington, has taken advantage of the Ocean Observatory Initiative's Regional Cabled Array, which consists of a network of underwater fiber optic cables. These cables typically transmit data for scientific research but can also capture seismic activity when disturbances occur.

"What we created is the starting point of any earthquake analysis," said Denolle, who emphasized the importance of their AI algorithms in enhancing the data collected from these cables. The study analyzed data from 285 earthquakes that occurred in Alaska's Cook Inlet in 2023, marking a critical step toward developing a foundational model for earthquake detection.

Co-author Qibin Shi, a seismologist at Rice University and former UW postdoctoral researcher, explained that the technology can detect even minor seismic events that might otherwise go unnoticed. "A well-trained model will identify earthquakes that the human eye cannot see," Shi noted, highlighting the capabilities of their advanced algorithm that isolates seismic signals from background noise.

The researchers validated their findings by testing their model at a site in Oregon, demonstrating that the technology could successfully operate alongside active data transmission, a significant improvement over previous methods that relied on inactive cables. This real-time data collection provides scientists with unprecedented access to seismic data, aiding in the understanding of plate tectonics and enhancing tsunami warning systems.

The implications of this research extend beyond academic interest. With the ongoing threat of earthquakes in the Pacific Northwest, improved detection systems could save lives and minimize property damage. By harnessing existing telecommunications infrastructure, researchers are paving the way for a more resilient response to natural disasters.

In addition to the University of Washington's team, the study included contributions from Ethan F. Williams, Bradley P. Lipovsky, William S. D. Wilcock, Deborah S. Kelley, and Katelyn Schoedl, all of whom played vital roles in the research. This study received funding from several organizations, including the National Science Foundation and the U.S. Geological Survey, underscoring its importance in advancing our understanding of seismic activity.

As researchers continue to refine this technology, they face challenges in managing the vast amounts of data generated. Denolle remarked, "The system is also portable, requiring just a modest amount of computing power to operate," indicating that further developments could enhance its applicability in various regions and conditions. The future of earthquake monitoring may very well rest on innovations like those demonstrated by this research, which provide a critical tool for understanding and responding to geological hazards.