Scientific Reuse of Submarine Telecommunications Cables: Implementation on a Portion of Pacific Cable TPC-1

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An international, collaborative project will be undertaken to investigate the potential multidisciplinary scientific use of undersea telecommunications cables that are being abandoned or retired by international telephone companies. Digital fiber optic technology has matured to the point where new fiber optic submarine telecommunications cables are replacing older analog coaxial types. The older cables still have decades of useful life and they represent an opportunity for scientific re-use as a tool for real-time, long-term oceanographic and geophysical observations on the deep seafloor. The study of global scale geophysical processes will increasingly require improved world-wide long-term monitoring of the oceans and underlying Earth. Having access to data in real-time will enhance many of these studies. Achieving these goals of broad spatial coverage, over long time periods using conventional instrumentation deployed from ships will be costly. Effective, real-time data telemetry via satellites and other means also has limitations. One possible alternative would be to use portions of ocean-spanning telecommunications cables scheduled to be retired in the next decade. They could be instrumented with sensors capable of monitoring certain geophysical properties. The cable could provide a source of reliable power, a means to acquire high bandwidth data in real time and provide a way to control remote instrumentation. The project deals specifically with TCP-1, an AT&T/KDD-owned Hawaii-Guam-Japan cable -- a portion of which has been turned over to IRIS and the University of Tokyo for use by the international academic research community. Plans are underway in Japan to initially instrument the Guam-Japan portion with seismometers and magnetometers. Work to be accomplished at the U.S.-owned Guam termination site is necessary before significant engineering efforts and installation of these instruments can be started. A small building for housing the electronics that power and control the seafloor repeaters will be constructed and the cable will be re-terminated within this building. A series of small pilot studies will also explore: 1) the feasibility of using academic research vessels rather than commercial cable ships to handle deep sea cables, 2) conceptual designs for a seafloor acoustic modem through which autonomous scientific instruments can be connected to a submarine cable, and 3) new, low-cost methods to couple data into a seafloor cable in situ. U.S. private industry is collaborating in that AT&T is transferring ownership of the TCP-1 cable to a consortium of academic research institutions, is making space and electrical power available at its Guam site, and is keeping the cable powered up during a one-year transition period.