What caused the volcanic tsunami that devastated a Greek island 373 years ago?

Enlarge / This view from an international volcano monitoring system shows the Kolumbo volcanic crater on the seafloor. (credit: SANTORY )

In 1650 CE, the Greek island of Santorini was devastated by the eruption of an underwater volcano called Kolumbo. People first noticed the water boiling and changing color and a cone poking out of the surface of the sea. Next came ejected glowing rocks, fire and lightning, fumes of thick smoke, falling pumice and ash, earthquakes, and a powerful tsunami with waves as high as 20 meters. All this eruptive activity killed around 70 people and hundreds of cattle.

These details are based on contemporary accounts compiled by French geologist Ferdinand A. Fouqué in 1879. A team of German and Greek scientists has now combined that historical knowledge with 3D seismic mapping and computer simulations to determine why the volcano's violent eruption triggered a tsunami. According to a new paper published in the journal Nature Communications, the tsunami resulted from a landslide followed by the volcanic explosion.

Located some 8 kilometers northeast of Santorini, Kolumbo also erupted around 1630 BCE with catastrophic consequences for ancient Minoan culture. Today, the volcano boasts sulfide-sulfate hydrothermal vents that are home to some rare species of microorganisms typically not found elsewhere near hydrothermal vents. And it remains active and potentially dangerous: A previously unknown magma chamber was discovered last year and is growing at a rate of around 4 million cubic meters per year. At that rate, the chamber will reach the same volume as the amount of magma ejected in the 1650 eruption within the next 150 years.