Small undersea volcanoes may unleash outsized tsunamis

An international team studied the 2022 Hunga eruption in Tonga and found that the rapid collapse of its roughly 4-km-wide caldera amplified a tsunami that reached 40 meters. Even small submarine calderas can generate dangerous tsunamis depending on collapse speed.

• Hunga's 4-km-wide caldera subsided nearly 1 km during the 2022 eruption
• The tsunami reached heights of 40 m within about 100 km of the source
• The collapse was piston-style: the floor dropped as a single block
• Losing just a quarter of the magma was enough to bring the reservoir roof down