Precise Tsunami Observation System in Deep Ocean by an Ocean Bottom Cable Network for the Prediction of Earthquakes and Tsunamis

The National Research Institute for the Earth Science and Disaster Prevention (NIED) started a project for the prediction of earthquakes and tsunamis by an ocean bottom cable network system in the Sagami trench in 1991. The system is composed of 6 seismographs and 3 tsunami gauges and expected to be completed by the end of March of 1996. After the installation of the system, it is expected that the hypocenters of. earthquakes whose magnitude are over 1.5 could be determined very accurately around the Kanto-Tokai area. Tsunami gauges could detect tsunamis with 1 mm resolution in deep ocean due to the thermal noise reduction treatments.