A coupled atmosphere-ocean source mechanism was a predictor of the 2022 Tonga volcanic tsunami

Volcanic tsunamis pose significant threats to nearby coastal communities. Despite extensive research, the mechanism behind tsunami generation remains unclear, and the ability to forecast a destructive tsunami has proven elusive. Here we present findings from the 2022 Tonga volcanic incident, showing that the leading air-pressure wave holds promise as a key predictor of tsunami behavior. We constructed an integrated atmosphere-ocean model to explain the underlying mechanism and validated it with various data, including satellite altimetry measurements. Contrary to prior hypotheses, our results reveal that: (1) the eruption process governs both the air-pressure and tsunami dynamics; and (2) the resulting crater volume controls the volcanic ejecta that produces the air-pressure waves, while the corresponding mass loss in the ocean triggers influxes of water into the crater, generating the tsunami. This study unveils a coupled atmosphere-ocean source mechanism in generating volcanic tsunamis and advocates for incorporating air-pressure sensors into early warning systems.