Using “Curie” – a 10,000-kilometer-long underwater fiber-optic cable connecting Los Angeles, California and Valparaiso, Chile – researchers have unveiled a new way to detect deep-sea and wave seismic activity at the surface of the ocean. The approach, which monitors the traffic that courses non-stop through networks of cross-border telecommunications cables, storm surge events and earthquakes over a nine-month observation period, has been successful. “This approach does not require any new infrastructure or instrument, but instead relies on the use of pre-existing ideas to use the telecommunications data obtained at the end of the process. pull a cable, ”William Wilcock wrote in a related comment. The new study suggests that the approach could transform our ocean-wide network of fiber optics into a real-time earthquake and tsunami detection and detection system. Monitoring seismic activity on the seabed is essential for studying the Earth’s crust and detecting offshore earthquakes and tsunami threats. However, the use and maintenance of geophysical instruments on the seabed is difficult and expensive, and as a result, underwater seismic stations are relatively rare in large areas of the ocean. A number of emerging technologies are being explored to address this data gap, including laser interferometry and diffuse acoustic sensing techniques that effectively transform telecommunication cables. trans-oceanic fiber-optic to kilometer-long seismic sensors. However, so far, these solutions have remained limited by the need for specialized laser detection equipment and “dark fiber.” According to Zhongwen Zhan and colleagues, if only a fraction of the million-kilometer submarine fiber optic network were used as geophysical sensors, significant improvements could be made in the amount of seismic data and coverage for large sections of the seabed. Zhan et al. demonstrate a new approach using the polarized light signals commonly used to broadcast information through optical telecommunication cables and the Curie submarine fiber optic cable, which crosses the eastern edge of the Curie Sea. Pacific Ocean between North and South America. Because light polarization is sensitive to temperature changes, the thermal stability of the seabed allowed the authors to monitor the constant optical telecommunication traffic and influence observed changes in seismic- and co-pressure. connected to the cable. Zahn et al. recorded ~ 30 ocean storm blow events and ~ 20 medium-to-large earthquakes over the nine-month continuous observation period, including a 7.4-magnitude earthquake event near Oaxaca, Mexico in June 2020.
###
For reporters interested in trends, several recent Science publications have demonstrated alternative methods for using telecommunication cables as geophysical sensors. A Report in Science in November 2019 showed that ocean and seabed dynamics can be monitored using Distributed Acoustic Sensing (DAS) in unused optical fiber, or “dark fiber,” in fiber cables. optic. https: /
Also, a Science Report in August 2018 showed how ultra-stable laser interferometry can be used to detect earthquake activity in both terrestrial and submarine fiber optic cables. https: /
Disclaimer: AAAS and EurekAlert! they are not responsible for the accuracy of press releases posted to EurekAlert! by sending institutions or for using any information through the EurekAlert system.