Multidisciplinary geophysical measurements on the ocean floor using decommissioned submarine cables: VENUS project

• Published in: IEEE journal of oceanic engineering Vol. 25; no. 1; pp. 111 - 120
• Main Authors: Kasahara, J., Shirasaki, Y., Momma, H.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.01.2000; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Arrays; Cables; Decommissioned; Earth sciences; Earth, ocean, space; Exact sciences and technology; Floors; Geophysical measurements; Geophysics; Geophysics: general, magnetic, electric and thermic methods and properties; Hydrophones; Instruments; Internal geophysics; Land; Marine; Observatories; Oceans; Performance evaluation; Scientific apparatus & instruments; Sea beds; Sonar equipment; Submarine cables; Telemetry; Undersea cables; Underwater cables; Venus; Pacific Ocean; Japan Sea; Philippine Sea; North Pacific; Geophysics; Reuse; Underwater cable; Measurement method; Real time; Telemetry; Ocean floors; Monitoring; Multidisciplinary
• ISSN: 0364-9059; 1558-1691
• DOI: 10.1109/48.820743

To perform geophysical and multidisciplinary real-time measurements on the ocean floor, it has been attempted to reuse decommissioned submarine cables. The VENUS project reuses the TPC-2, which is one of these systems and runs across the entire Philippine Sea Plate between Guam Island and Okinawa Island. The VENUS system comprises an ocean floor observatory, a submarine cable, and a land system. The major components of the ocean floor observatory are geophysical instruments and a telemetry system. There are seven scientific instrument units including broadband seismometers and a hydrophone array. Digital telemetry using the old analog telephone cable obtains high data accuracy and real-time accessibility to data from a laboratory on land. The bottom-telemetry system and a part of sensor units were installed at a depth of 2157 m on the landward slope of the Ryukyu (Nansei-Syoto) Trench on August 29, 1999. The data from the hydrophone array and tsunami gauge have been correctly transmitted to the data center. The rest of the scientific instruments will be deployed by deep-tow equipment and a remotely operated vehicle. Using a decommissioned submarine cable will greatly reduce construction costs compared to using a new cable system.