Tsunami waves induced by the atmospheric pressure disturbance originating from the 2022 volcanic eruption in Tonga

On January 15, 2022, a violent eruption of Tonga volcano formed an explosion-like atmospheric shock wave, and subsequently many parts of the Pacific coast were hit by tsunami waves. This study focuses on the leading tsunami wave tightly linked with the widespread atmospheric pressure disturbance, and attempts to reveal whether the notable tsunami waves along the coast of Japan are attribute to the mechanism of Proudman resonance. It can be clearly shown that a pressure disturbance radiating from the volcanic eruption spread rapidly over the Pacific Ocean with an average speed of 309 m/s, while a group of tsunami waves appeared closely following the atmospheric disturbance. In most area of the Pacific Basin, the pressure disturbance moved too fast to excite the Proudman resonance, which is proved by the DART data in the deep ocean. The leading tsunami wave associating with the pressure disturbance was several centimeters high in deep ocean, but could be more than 20 cm along the coast of Japan. Based on the analysis of observation data and numerical simulation, it is revealed that the nearshore amplification instead of the Proudman resonance plays the dominant role in producing the threatening nearshore tsunamis, which may not be easily detected and aware by deep water buoys.