Abstract
Several tsunami waves whose maximum tsunami height is about 2.6 m are estimated to hit Okayama city under Nankai Trough earthquake. Elevation is below sea level in almost all of the city's coastal area. Therefore, severe tsunami disaster is expected there. The previous research shows tsunami waves propagating from Kii Channel vir Naruto and Akashi Channel hit Okayama city's offshore. In this research, a simple method for realtime forecast of tsunami behavior in Okayama city's coast using tsunami waveform observed at entrance of Kii Channel is considered on the purpose of contributing to enhancing the city's prompt tsunami countermeasure under the earthquake. It is concluded that tsunami height and tsunami arrival time in Okayama city's offshore are precisely predicted in many earthquake's cases mainly using regular waves extracted by Fourier analysis from waveform data obtained at Kii Channel.
