Seasonal and Geographical Variations in the Quantified Relationship Between Significant Wave Heights and Microseisms: An Example From Taiwan

Investigating significant wave heights (SWHs) predicted from microseisms can complement climate observations and provide information about the interaction of sea storms with coastal environments. By comparing the spectrogram calculated from the data of inland seismic stations and SWHs recorded by buoys around Taiwan, we discern seasonal and geographical differences while estimating wave height with an empirical law. A monthly analysis based on nine seismic stations and buoy pairs shows an approximately linear relationship between the square root of the seismic energy and the wave heights during summer for most stations and a nonlinear relationship in winter. The high correlation coefficient of over 0.8 between the seismic energy and SWHs in winter indicated that direct effects from weather conditions are the primary factor influencing microseism behavior. Although the station in southernmost Taiwan revealed microseism energy distribution similarly to that of other stations, the wave-height fluctuation was distinct, showing slight variations in winter. This observation could relate to the shielding effect of the land topography, which prevents infiltration by strong winds and decreases the ramifications of wave height. This work assesses the possibility of estimating significant sea wave heights around Taiwan and the importance of seasonal and geographical variation while selecting parameters.