A devastating eruption in the Mediterranean?

Article science and Future Jacques-Marie Bardintzeff

The calm, azure waters of the Mediterranean are deceptive, because deep below the surface a multitude of tectonic plates collide in this confined space subject to significant compressive and shear stresses. The mountainous reliefs and active volcanoes that mark much of the Mediterranean landscape are, in fact, only the emerging witnesses to the formidable plate movement that animates this region of the globe.

The Mediterranean, a very active region

One of the most active regions is undoubtedly the eastern part of the Mediterranean. In this area, the African plate sinks under the Aegean plate and the Anatolian block (Turkey, Eurasian plate), being pushed by the northward rise of the Arabian plate.

“A magmatic reservoir that will eventually fill up “

With regular seismic and volcanic manifestations, it is not surprising that this area is subject to increased scientific monitoring. It is the Kolumbo volcano that has this time attracted the attention of researchers following a seismic measurement campaign at sea. This volcano lies some 500 metres below the surface of the water. It is even the most active underwater volcano in the Mediterranean.

With regular seismic and volcanic manifestations, it is not surprising that this area is subject to increased scientific monitoring. It is the Kolumbo volcano that has this time attracted the attention of researchers following a seismic measurement campaign at sea. This volcano lies some 500 metres below the surface of the water. It is even the most active underwater volcano in the Mediterranean.

Thanks to a new technique for processing seismic data, scientists have demonstrated a significant increase in the amount of magma present in the magma chamber. According to the results published in the journal Geochemistry, Geophysics, Geosystems, the volume would also be on track to reach what would have caused the last eruption in the year 1650. What to fear from a volcano revival …

According to seismic data, the magma reservoir beneath the volcano may have reached 1.4 km 3.

If the increase in volume continues at the same rate as at present, the reservoir should reach 2 km 3 within 150 years, which is the volume involved in the last eruption 400 years ago. However, it is impossible to know when exactly the volcano will erupt. It may be much earlier, or much later. In any case, scientists warn of the need to establish continuous monitoring of the region as quickly as possible.

Indeed, Kolumbo is characterised by high-powered explosive eruptions and the fact that it is an underwater volcano does not make it any less dangerous, on the contrary: the eruption could produce a tsunami and significant ash fallout. It could therefore be relatively similar to the eruption of Hunga Tonga, which marked both the beginning of the year 2022. Although smaller in magnitude, this explosion could also prove much more disastrous. In fact, unlike Hunga Tonga, Kolumbo is located only 7 km from the densely populated coast of the island of Santorini and Greece.