The January 15th 2022 eruption of the Hunga-Tonga volcano was one of the most powerful volcanic explosions in recent decades. This study uses data from global seismic networks to analyze the eruption's time evolution, the propagation of atmospheric waves, and the low-frequency seismic signals following the event. The eruption, beginning around 04:00 UTC, involved two large explosions at 05:30 and 08:25 UTC, generating atmospheric waves that circled the Earth multiple times and were seismically detected. The study also identifies very low-frequency signals lasting several hours, interpreted as the excitation of Earth's normal modes. This represents an unprecedented example of atmosphere-solid Earth coupling over such a long duration and one of only a few examples of normal mode excitation following volcanic eruptions.

Jordi Diaz