Development of a Tsunami-tide Interaction Model with Simulation of Tsunami Wave Propagation to Korea Coasts

Abstract

Kim, K.O.; Jung, K.T., and Ha, T.M., 2021. Development of a tsunami-tide interaction model with simulation of tsunami wave propagation to Korea coasts. In: Lee, J.L.; Suh, K.-S.; Lee, B.; Shin, S., and Lee, J. (eds.), Crisis and Integrated Management for Coastal and Marine Safety. Journal of Coastal Research, Special Issue No. 114, pp. 91–95. Coconut Creek (Florida), ISSN 0749-0208. Simulation studies of historic and prognostic tsunamis have been performed with a focus on tsunami-tide interactions. A modeling system based on the 3D POM (Princeton Ocean Model) has been developed that is composed of a global tsunami model and a regional multinesting tide/tsunami/tsunami-tide interaction model covering the Northwest Pacific region. Propagations of two historic tsunamis, the 2010 Chilean and 2011 Tohoku tsunamis, were simulated to estimate the effects of tsunami-tide interactions by comparing the results from tsunami-only and tsunami simulations with tide simulations. Calculations show that tsunami waves are significantly transformed after traveling a long distance and subsequently affected by the tidal phase. As prognostic tsunami propagation, the Nankai Trough earthquake-induced tsunami wave in Japan was investigated. A series of calculations were performed with a systematic shift of the tsunami occurrence time. The effects of tsunami-tide interactions were examined in terms of local tidal phase changes, focusing on the changes in the first tsunami heights and occurrence times arriving at the selected tidal stations in Korea. The tsunami-tide interaction mostly results in a positive change in the tsunami first peak heights with a maximum change near low tide probably due to the interaction between the tsunami-induced current and tidal current. The water depth increase near high tide advances the arrival of the tsunami first peaks, whereas the water depth decrease near low tide delays the arrival of the tsunami first peaks.