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“Surprise” Magma Chamber Discovered Bubbling Under Active Mediterranean Volcano

The last time Kolumbo erupted, it wasn't pretty.


Tom Hale


Tom Hale

Senior Journalist

Tom is a writer in London with a Master's degree in Journalism whose editorial work covers anything from health and the environment to technology and archaeology.

Senior Journalist

Bubbling water and Submarine volcanic activity near Kolumbo underwater volcano in Santorini, Greece.

Submarine volcanic activity along a section of the Kolumbo crater on the seafloor. Image credit: SANTORY

A new magma chamber bubbling beneath an active submarine volcano off the coast of Greece has been discovered. While it doesn’t necessarily mean the volcano poses an immediate danger, the magma chamber's discovery suggests the underwater volcano has the potential to reach "boiling point" within the next two centuries. 

An international team of researchers used full-waveform inversion seismic imaging to reveal the magma chamber beneath Kolumbo, an active submarine volcano near the Greek island of Santorini.


“Full-waveform inversion is similar to a medical ultrasound. It uses sound waves to construct an image of the underground structure of a volcano,” Dr Michele Paulatto, a volcanologist at Imperial College London and second author of the study, explained in a statement.

Kolumbo's last eruption was almost four hundred years ago in 1650 CE. The pyroclastic flows and surges mounted over the sea surface, killing 70 people on the island of Santorini as a result of toxic gases. This deadly eruption was driven by swelling magma reservoirs beneath the surface of Kolumbo. 

With the addition of this previously unidentified chamber, the researchers believe that molten rock in the chamber is reaching a similar volume to that seen in the 17th century.

Sunset over Mediterranean near the Greek island of Santorini with white villas on mountaside.

Kolumbo can be found in the waters near the Greek island of Santorini. Pretty, ain't it? Image credit: Feel good studio/

The researchers explain that existing data for submarine volcanoes in the region is lacking and by no means complete. However, recent imaging has been able to acquire a much more detailed illustration of what’s going on down there. 


Most notably, it picked up on a large magma chamber that has been growing at an average rate of roughly 4 million cubic meters (141 million cubic feet) each year since Kolumbo’s last eruption in 1650 CE. 

All in all, that’s around 1.4 cubic kilometers (0.33 cubic miles) of magma. If this current rate of growth continues, it could reach 2 cubic kilometers (0.4 cubic miles) of melt volume within the next 150 years – about the same amount that was estimated to be ejected during the 1650 CE eruption.

The study authors stress that there’s no way to accurately predict when the volcano might blow its load. Nevertheless, the study highlights how research like this could help to better understand the risk of an eruption – and, in turn, potentially save lives. 

“We need better data on what’s actually beneath these volcanoes,” Kajetan Chrapkiewicz, a geophysicist at Imperial College London and lead author of the study. “Continuous monitoring systems would allow us to have a better estimation of when an eruption might occur. With these systems, we would likely know about an eruption a few days before it happens, and people would be able to evacuate and stay safe.”


The new study was published in the AGU’s journal Geochemistry, Geophysics and Geosystems. 


natureNaturenatureplanet earth
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