Abstract: In this study we analyzed the sea level data from two pressure-based gauges in Sanya Bay and Guanghai Bay of Taishan to investigate the tsunami waveforms of two major tsunamis, the 2010 Chile and the 2011 Japan events. With the sea level data from two deep-ocean assessment and reporting of tsunamis (DART) stations, we focused on the far-field characteristics of tsunami waves on the coast of South China. Fourier power spectrum and wavelet analysis were used to describe the timing and spectral content of the tsunami signals. The tsunami waves of both events arrived at the coast of South China in 3~4 hours after entering the Bashi Channel. The similarities and differences between the tsunami signals of the two events were then compared to highlight the tsunami response characteristics of local topography. Spectral content of certain periods were amplified during tsunami transformation and evolution. Tsunami waves can oscillate, lasting for over 2~3 days in the bays with signals of longer period having longer duration. Though these two tsunami events did not pose disastrous impact on our coast, this study provides a comprehensive analysis of far-field tsunami characteristics on the coast of South China and will be of value for future tsunami hazard assessment.

Key words: earthquake-triggered tsunami, Chile, Japan, tsunami waveform, spectral analysis, wavelet analysis, coast of South China