DEVELOPMENT AND OPERATION OF THE JAPANESE TSUNAMI OBSERVATION SYSTEM BY USING NATIONWIDE COASTAL WAVE GAUGES

Abstract

This paper introduces development and improvement of the Japanese offshore tsunami profile observation system using seabed installed acoustic wave sensor network named as NOWPHAS (NOWPHAS: Nationwde Ocean Wave network for Ports and HArbourS). Recent observed tsunami profiles caused by the 1993 Hokkaido-Southwest-Off Earthquake, 1994 Hokkaido-East-Off Earthquake, and the 2003 Tokachi-Off Earthquake were introduced. Development of the new wave gauges including the DWDM (Doppler-type Wave Directional Meter) and the new GPS buoy system was described. New NOWPAHS data communication system design using the internet network was also shown.