An international team of scientists led by Dr. Steffen Catterolf from the GEOMAR Helmholtz Center for Ocean Research in Kiel has presented a discovery that could change our understanding of the volcanic history of the island of Santorini.

Santorini was formed after the devastating Minoan eruption about 3,600 years ago, which created the famous caldera walls. But new data shows that this was not the only major eruption in the island’s history.

Expedition IODP 398, conducted aboard the drillship JOIDES Resolution, brought important evidence of this underwater eruption. After drilling up to 300 meters deep inside the caldera, scientists discovered layers of gray pumice and ash up to 40 meters thick, directly related to the event in 726 BC. e. Interestingly, the eruption likely occurred largely underwater, consistent with historical eyewitness accounts and confirming that the sea was boiling and covered with blocks of pumice, Nature Geoscience (NG) reports.

These new data have important implications for assessing risks and developing hazard reduction strategies. Given that large explosive eruptions can occur even in the early stages of caldera cycles, more attention needs to be paid to submarine volcanic processes and their potential consequences.