||Chilean earthquake occurred on 27 Feb. 2010 with magnitude 8.8 Mw. On 11 March, 2011 another strong earthquake occurred in northeastern Japan with magnitude 9.1 Mw. These two earthquakes both triggered tsunami, causing serious casualties. In this study, a numerical tsunami model COMCOT developed by Department of Civil and Environmental Engineering, Cornell University, USA, is used to simulate these two big tsunamis. The results are validated by comparing with tidal station data provided by Center of Harbor and Marine Technology. Then the simulated water level is analyzed by two-dimensional Fast Fourier Transform (2D-FFT) and compared with the dispersion relation of edge waves to identify the edge wave mode. The data of Center of Harbor and Marine Technology for each commercial harbor is analyzed by the algorithm developed by Chen et al. (2012). The purpose is to see if edge waves were generated because, instead of the wave impact from the sea, edge wave may affect the lateral side of coastal structures.|
According to the simulation and the in-situ measurements, the first tsunami wave arrived six commercial harbors in the following: Hualien, Suao, Keelung, Kaohsiung, Anping and Taichung. In both tsunamis, the maximum tsunami wave height in Kaohsiung was both higher than the maximum tsunami wave height in the east coast. Both the analyses of 2D-FFT and the algorithm of Chen et al. (2012) suggests edge waves of Stokes mode were generated in both tsunamis.