Hunga Tonga volcano eruption caused massive seafloor collapse

A study published in Nature Geoscience has reconstructed the massive seafloor transformation caused by the Hunga Tonga-Hunga Ha’apai volcanic eruption on January 15, 2022. The eruption caused the volcano's caldera to collapse abruptly, sinking nearly 700 meters in depth.

Before the event, the caldera was between 150 and 200 meters deep with a diameter of approximately 4.5 kilometers. Following the eruption, the floor descended to about 850 meters, and the diameter expanded to roughly 4.8 kilometers. In some northwestern sectors, the terrain dropped between 800 and 1,100 meters.

The collapse displaced approximately 8.9 cubic kilometers of material. Researchers determined that the rapid, piston-like descent of the caldera floor was a primary driver in generating the destructive tsunami, which produced waves exceeding 40 meters in height in areas within 100 kilometers of the volcano. The eruption also sent ash and steam 55 kilometers into the atmosphere and created atmospheric pressure waves that traveled globally.