Reuse of submarine cable for seismic and geoelectrical measurements

Efforts have been initiated to reuse a former submarine telephone cable (“TPC-1” retired in 1991) for undersea scientific measurements. TPC-1 runs from Ninomiya, Japan to Guam, U.S.A., and has a length of ca. 2700 km with the strike almost in the N-S direction. A prototype instrument package was successfully installed in northern Japan at a depth of 100 m using a similar coaxial cable. An instrumental package has been built and will be deployed near 30°N next year. The instrument has three component accelerometers with 24 bit A/D converters, a hydrophone applying analog telemetry, and a quartz thermometer and a quartz pressure sensor with a data length of 16 bits. The data will be transmitted to the Ninomiya station in real-time. Other plans to reuse submarine telephone cables have been considered between Naoetsu, Japan and Nakhodka, Russia and between Okinawa, Japan and Guam