The extreme winds of tropical cyclones generate high waves over the ocean, causing severe damage to offshore facilities and coastal communities. Disaster mitigation requires accurate prediction and forecasting of the highest potential waves. However, the physics of wave development is not fully understood, and the number of mid-ocean observations during extreme tropical cyclones is extremely insufficient. Therefore, physically and statistically evaluating the highest potential waves is difficult. However, ocean waves excite seismic noise (microseisms). Although source sites of microseisms under specific tropical cyclones have been identified by case studies, the extreme ocean wave magnitude under tropical cyclones have not been systematically analyzed using long-term historical records. Here, we, for the first time, utilize long-term microseisms observed by seismic observation networks to associate the historical maximum microseisms events with the highest tropical cyclone-generated wave events around Japan. We show that Typhoon Wipha in 2013, Typhoon Lan in 2017, and Typhoon Hagibis in 2019 were the maximum microseisms events in the past 20 years based on microseism energy within an 8-10 s period. We associate the events with the highest wave heights and the largest wave-induced sea surface pressures generated by tropical cyclones. Although ocean wave models have a large uncertainty of tropical cyclone-generated extreme waves, microseisms observations can endorse the results of an ocean wave model even if lack of direct ocean wave observation under tropical cyclones. Furthermore, rich information of microseisms on wave development and propagation has a potential to proceed understanding of the extreme wave physics.
