EGU21-6445, updated on 04 Mar 2021
https://doi.org/10.5194/egusphere-egu21-6445
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Towards multi-method geophysical sensing on submarine cables 

Zhongwen Zhan1, Mattia Cantono2, Jorge Castellanos1, Miguel González Herráez3, Zhensheng Jia4, Valey Kamalov2, Hugo Martins3, Antonio Mecozzi5, Rafael Müller2, Zhichao Shen1, Ethan Williams1, and Shuang Yin2
Zhongwen Zhan et al.
  • 1Seismological Laboratory, California Institute of Technology, USA
  • 2Google LLC., USA
  • 3Department of Electronics, University of Alcalá, Polytechnic School, 28805 Alcalá de Henares, Spain
  • 4CableLabs, Louisville, USA
  • 5Department of Physical and Chemical Sciences, University of L’Aquila, ITALY

The oceans present a major gap in geophysical instrumentation, hindering fundamental research on submarine earthquakes and the Earth’s interior structure, as well as effective earthquake and tsunami warning for offshore events. Emerging fiber-optic sensing technologies that can leverage submarine telecommunication cables present an new opportunity in filling the data gap. Marra et al. (2018) turned a 96 km long submarine cable into a sensitive seismic sensor using ultra-stable laser interferometry of a round-tripped signal. Another technology, Distributed Acoustic Sensing (DAS), interrogates intrinsic Rayleigh backscattering and converts tens of kilometers of dedicated fiber into thousands of seismic strainmeters on the seafloor (e.g., Lindsey et al., 2019; Sladen et al., 2019; Williams et al., 2019; Spica et al., 2020). Zhan et al. (2021) successfully sensed seismic and water waves over a 10,000 km long submarine cable connecting Los Angeles and Valparaiso, by monitoring the polarization of regular optical telecommunication channels. However, these new technologies have substantially different levels of sensitivity, coverage, spatial resolution, and scalability. In this talk, we advocate that strategic combinations of the different sensing techniques (including conventional geophysical networks) are necessary to provide the broadest coverage of the seafloor while making high-fidelity, physically interpretable measurements. Strategic collaborations between the geophysics community and telecommunication community without burdening the telecomm operation (e.g., by multiplexing or using regular telecom signals) will be critical to the long term success.

 

Marra, G., C. Clivati, R. Luckett, A. Tampellini, J. Kronjäger, L. Wright, A. Mura, F. Levi, S. Robinson, A. Xuereb, B. Baptie, D. Calonico, 2018. Ultrastable laser interferometry for earthquake detection with terrestrial and submarine cables. Science, eaat4458.

Lindsey, N.J., T. C. Dawe, J. B. Ajo-Franklin, 2019. Illuminating seafloor faults and ocean dynamics with dark fiber distributed acoustic sensing. Science. 366, 1103–1107.

Sladen, A., D. Rivet, J. P. Ampuero, L. De Barros, Y. Hello, G. Calbris, P. Lamare, 2019. Distributed sensing of earthquakes and ocean-solid Earth interactions on seafloor telecom cables. Nat Commun. 10, 5777.

Spica, Z.J., Nishida, K., Akuhara, T., Pétrélis, F., Shinohara, M. and Yamada, T., 2020. Marine Sediment Characterized by Ocean‐Bottom Fiber‐Optic Seismology. Geophysical Research Letters, 47(16), p.e2020GL088360.

Williams, E.F., M. R. Fernández-Ruiz, R. Magalhaes, R. Vanthillo, Z. Zhan, M. González-Herráez, H. F. Martins, 2019. Distributed sensing of microseisms and teleseisms with submarine dark fibers. Nat Commun. 10, 5778.

Zhan, Z., M. Cantono, V. Kamalov, A. Mecozzi, R. Muller, S. Yin, J.C. Castellanos, 2021. Optical polarization-based seismic and water wave sensing on transoceanic cables. Science, in press.

How to cite: Zhan, Z., Cantono, M., Castellanos, J., González Herráez, M., Jia, Z., Kamalov, V., Martins, H., Mecozzi, A., Müller, R., Shen, Z., Williams, E., and Yin, S.: Towards multi-method geophysical sensing on submarine cables , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-6445, https://doi.org/10.5194/egusphere-egu21-6445, 2021.

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