Krakatau's 1883 eruption, which killed over 30,000 people, is a stark reminder that volcanic disasters are not just about direct lava flows. A tsunami, triggered by the same event, was responsible for many of the casualties.

Undersea volcanoes can be particularly unpredictable. While deep-sea eruptions are often less explosive, those closer to the surface can cause violent explosions due to lower water pressure. The exact conditions under which volcanic activity leads to a tsunami remain poorly understood, especially for caldera-forming eruptions.

The 2022 Hunga eruption in Tonga, where a 4-kilometer-wide caldera collapsed, created a massive 40-meter-high tsunami within 100 kilometers of the source. This event underscores the potential danger posed by underwater volcanoes, even when they’re relatively small.

Researchers caution that the dynamics of submarine eruptions and the associated tsunamis are not well understood, making it difficult to predict and prepare for such events. While the Hunga eruption is a prime example, other undersea volcanoes could similarly pose a threat, highlighting the need for further research and better understanding of these hidden dangers.