Noise Levels and Signals Observed on Submarine Fibers in the Canary Islands Using DAS

Autor: Miguel González Herráez, Mario Ruiz Fernández, Carlos Becerril, Hugo F. Martins, César R. Ranero, Antonio Villaseñor, Arantza Ugalde, Sonia Martin-Lopez
Přispěvatelé: Agencia Estatal de Investigación (España), Comunidad de Madrid, European Research Council, Ministerio de Ciencia, Innovación y Universidades (España)
Jazyk: angličtina
Předmět:
Zdroj: Digital.CSIC. Repositorio Institucional del CSIC
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ISSN: 1938-2057
0895-0695
DOI: 10.1785/0220210049
Popis: 13 pages, 10 figures, supplemental material https://doi.org/10.1785/0220210049.-- Data and resources: CANALINK-Canarias submarine link S.L. (http://www.canalink.tel/; last accessed February 2021) provided the information on the cable structure. EMODnet Bathymetry Consortium (2020) provided bathymetric data.-- This is a contribution of the Barcelona Center for Subsurface Imaging that is a Grup de Recerca de la Generalitat de Catalunya
In this study, we investigate 70 days of distributed acoustic sensing (DAS) recordings in the Canary Islands using an undersea fiber‐optic telecommunication cable that links the islands of Tenerife and Gran Canaria. Two DAS interrogators connected to both ends of the cable turned the fiber into an array of 11,968 strain sensors covering a total length of ∼120 km. We present the details of the experiment, noise analysis, and examples of recorded signals. Seismic ambient noise levels assessment indicates poor local coupling of the cable due to the irregular bathymetry that results in high‐amplitude acoustic oscillations in some channels. The DAS array recorded several types of nonseismic (vehicles, surface gravity waves, ships) and seismic signals. Local and regional earthquakes were detected with magnitudes mbLg≥2⁠. Surface waves from teleseismic events at a distance of ∼3000 km were also identified in the strain recordings. Here, we report the first observations with DAS of hydroacoustic T waves generated by oceanic earthquakes located at the Central Mid‐Atlantic Ridge and the Cape St. Vincent region. Events had magnitudes from Mw 4.2 to 6.9, and the hydroacoustic waves were recorded at epicentral distances from 780 to 3400 km. Our findings show that submarine fiber‐optic cables can effectively be used to assess the seismic activity in remote oceanic areas
With funding from the Spanish government through the “Severo Ochoa Centre of Excellence” accreditation (CEX2019-000928-S), Comunidad de Madrid and FEDER Program under grant SINFOTON2-CM:P2018/NMT-4326, the European Research Council (OCEAN-DAS: ERC-2019-POC-875302), the Spanish Government under projects RTI2018-097957-B-C31, and RTI2018-097957-B-C33. M.R.F.R. and H.F.M. acknowledge financial support from the Spanish MICINN under contract no. IJC2018-035684-I, and IJCI-2017-33856, respectively
Databáze: OpenAIRE
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