Optical interferometry–based array of seafloor environmental sensors using a transoceanic submarine cable

Abstract

Optical fiber–based sensing technology can drastically improve Earth observations by enabling the use of existing submarine communication cables as seafloor sensors. Previous interferometric and polarization-based techniques demonstrated environmental sensing over cable lengths up to 10,500 kilometers. However, measurements were limited to the integrated changes over the entire length of the cable. We demonstrate the detection of earthquakes and ocean signals on individual spans between repeaters of a 5860-kilometer-long transatlantic cable rather than the whole cable. By applying this technique to the existing undersea communication cables, which have a repeater-to-repeater span length of 45 to 90 kilometers, the largely unmonitored ocean floor could be instrumented with thousands of permanent real-time environmental sensors without changes to the underwater infrastructure.

Linking Distributed and Integrated Fiber‐Optic Sensing

“…In principle, this type of measurement is consistent with systems employed by other authors, such as Marra et al. (2018, 2022), though the technical details of the systems will vary. Other authors measure accumulated changes in polarization as a different observable (Mecozzi et al., 2021; Zhan et al., 2021), but even then, the resulting measurement of interest to geoscientists remains one of integrated strain or strain rate.…”

High resolution seafloor thermometry for internal wave and upwelling monitoring using Distributed Acoustic Sensing

“…When implemented, the SMART cable initiative [97] should provide calibrated temperature sensors at the optical repeaters of new cables. It is also worth reminding the significant efforts and recent progress on the improvement of the sensing range, SNR characteristics and the simultaneous use of DAS instruments on operating telecommunication fibers [21,94,98,99,100,101,102]. Although…”

Recent Advances in Triboelectric Nanogenerators for Marine Exploitation

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