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Global Tonga tsunami explained by a fast-moving atmosperic source

In the article “Global Tonga tsunami explained by a fast-moving atmospheric source” published in Nature, Omira et al. (2022) addressed the global reach of the tsunami that followed the colossal explosion of the Hunga Tonga-Hunga Ha'apai volcano on January 15th 2022. This was the first global volcano-triggered tsunami recorded by modern, worldwide and dense instrumentation and, thus, providing a unique opportunity to investigate the atmosphere-ocean coupling processes in the tsunami generation, propagation and amplification. Omira et al. (2022) used sea-level, atmospheric and satellite data from across the globe, along with numerical and analytical models, to demonstrate that the Tonga tsunami was driven by a constantly moving source in which the acoustic-gravity waves radiating from the eruption excite the ocean and transfer energy into it via resonance. Their findings have clear hazard implications as the Tonga tsunami exhibited exceptional characteristics (i.e., higher propagation speeds, amplification in the deep ocean, unexpected wave heights in the far-field, and an unprecedented duration). They also bring to the fore the need to revisit the forecast capabilities of the tsunami early-warning systems currently in place.

a, Optical (top) and infrared channel 13 (bottom) from the GOES-17 satellite imagery showing the onset and expansion of the Hunga Tonga–Hunga Ha’apai volcanic explosion and cloud, from 04:00 to 05:20 UTC. Optical imagery from NOAA/NESDIS/STAR visualized by NASA Worldview. b, Detail at 5:10 UTC, with clean and interpreted optical (top pair) and clean and interpreted infrared channel 13 (bottom pair) imagery. Note the visible (although faded) effects of the rapidly expanding acoustic-gravity waves triggered by the colossal explosion of the volcano.

Omira, R., Ramalho, R.S., Kim, J., González, P. J., Kadri, U., Miranda, J. M., Carrilho, F., Baptista, M .A. (2020). Global Tonga tsunami explained by a fast-moving atmospheric source. Nature (2022).

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