Idealized animation of tsunamis in the Kingdom of Tonga looking north-northeast
Idealized animation of tsunamis produced by the 15 January 2022 eruption of Hunga Tonga-Hunga Ha‛apai volcano in the Kingdom of Tonga. View to the north-northeast.
The fastest water wave to radiate away from the eruption is being pushed by an atmospheric Lamb wave triggered by the explosion. (Water waves created by atmospheric gravity waves close behind the Lamb wave have been omitted to keep the animation simple.)
The water wave grows bigger (amplification) over the deep Tonga Trench, then decouples from the atmospheric wave on the east side of the trench, creating a series of new, decoupled waves. Together, the coupled and decoupled waves constitute a meteotsunami. Far behind them, the “classic” tsunami is produced by seafloor changes displacing a large volume of water during the eruption.