Determination of Accurate Arrival Time of Meteotsunami Event in Yellow Sea

According to a recent study by the Korean Meteorological Administration (KMA), unforeseen losses to property and human lives along the west coast of Korea in March 2007 were caused by meteotsunamis that originated at Shandong, which is located in eastern China. The determination of the arrival time of meteotsunamis in Yellow Sea is very important to protect human life and limit economic losses in coastal areas, because the analysis of meteotsunami propagation is primarily dependent on the method of arrival time. In this study, the meteotsunami event of March 2931, 2007, the most powerful meteotsunami event reported in the Yellow Sea, was selected to find the optimal method of calculating the meteotsunami arrival time. It is difficult to estimate the arrival time of a meteotsunami that is commonly observed as a non-stationary signal in a time series without any specific criterion. To find a quantitative and reasonable method of estimating the arrival time, the propagation direction of the meteotsunami was analyzed using the arrival time at each tidal station derived from the absolute and relative threshold of the sea level oscillations in the meteotsunami frequency bands. The results indicated that the meteotsunami propagation derived using the relative threshold which defines the arrival time as the time when the amplitude of the sea level oscillation exceeds 3 standard deviations was more similar to the propagation pattern of the high rain rate field than other thresholds.