Santorini: Investigations have shown an unknown, huge underwater volcanic eruption

An unknown until today underwater volcanic eruptionone of bigger ones in the volcanic arc of the southern Aegean, researches have brought to light multinational scientific group at Santorini.

The scientific team identified one giant pumice depositwhich was sampled at seven underwater locations around the island of Santorini.

This pumice layer named “Ancient Tuff” indicates that a shallow underwater eruption of the prehistoric Santorini volcano took place about 520 thousand years ago (with a possible deviation of ten thousand years).

The results are published in the journal Communications Earth & Environment of the Nature group.

Six times bigger than the great Minoan explosion

Fine volcanic pumice deposits from the eruption they covered three islands.

Pyroclastic flows erupted under the sea carried water and turned into turbidity and mud currents that covered the seabed up to 70 kilometers away from their source forming a submarine deposit with a volume greater than about 90 cubic kilometers and a thickness of up to 150 meters.

Impressive is the fact that this deposition is six times greater than the pyroclastic flow deposits of the great Minoan eruption which occurred during the Late Bronze Age (about 3,600 years ago) and contributed to the decline of the Minoan civilization of Crete.

According to the new data, the volcanic field Christiana-Santorini-Kolumbo it was much more explosive in the distant past than has been previously known.

However, the researchers clarify that despite this violent early history, it is very amazing the volcanic complex of Santorini to have once again big explosion in the near future.

A combination of deep drilling, large interdisciplinary datasets, laboratory analysis and a dense network of marine seismic profiles was used to discover the subsea pumice deposit.

The mission was carried out by the research vessel JOIDES Resolution Science Operator, which is used by the international research program IODP.

Tthe program is supported by 22 countries with the aim of exploring the history and structure of the Earth, as recorded in the sediments and bottom rocks. In this particular oceanographic mission number 398, which was carried out from December 2022 to February 2023, they participated 32 scientists from nine countries, led by Tim Druitt from France’s Université Clermont-Auvergne and Stephen Kouterolf from the Geomar Helmholtz Center for Oceanographic Research in Kiel. The scientific team also participated, the associate professor of the Department of Geology and Geoenvironment of the National and Kapodistrian University of Athens, Paraskevi Nomiko, the lecturer in the Department of Geology of the Aristotle University of Thessaloniki, Olga Koukousioura, and the researcher of the Department of Environmental Microbiology of the Hellenic Center for Marine Research, Paraskevi Polymenakou.

As Mrs. Nomikou characteristically points out in APE-MPE, “the geological history of Santorini is being written again!».

“Findings from undersea research drilling change the current understanding of the southern Aegean volcanic arc by revealing an extremely dangerous undersea volcanic activity than previously known. They extend the explosive history of the Santorini volcanic complex into the past and suggest the existence of a large buried submarine caldera, on which its modern volcanic field is evolving,” she emphasizes.

Also, Ms. Nomikou explains that the existence of these ash deposits on land “highlights the importance of deep subsea drilling to reveal all the secrets of island volcanic arcs, especially in densely populated areas such as the Mediterranean.”