SANTORINI – While tourists to Santorini can gaze at the sunken dormant volcano Caldera, a threat is growing at a nearby underwater active volcano called Kolumbo, where scientists said a giant magma chamber has been discovered growing.

They published a study on the chamber in the American Geophysical Union’s Geochemistry, Geophysics, and Geosystems said it poses a risk of reaching a critical point and exploding, sometime in the next 150 years.

They called it a “serious threat,” reported Nature Journal, and that the magma chamber under Kolumbo increases the chances of a future eruption. They believe it could reach a critical point in the next 150 years and pose a “serious threat.”

Kolumbo last erupted in 1650 when an explosion breached the sea surface and killed 70 people, breaking through after magma reservoirs beneath the volcano continued to grow and accumulate at a large scale.

Scientists believe that this previously undiscovered magma chamber is growing at an average rate of roughly 4 million cubic meters per year since the submarine volcano last erupted. The amount of melt in there is now 1.4 cubic kilometers (0.33 cubic miles,) the study reported, said Newsweek.

It is now reaching a similar volume that caused the 1650 eruption, meaning another big eruption is due as its rate of growth counteracts its cooling and crystallization processes, the triggering mechanism.

While not able to accurately predict when Kolumbo will erupt again, the scientists said there should be better monitoring facilities near the volcano which is only five miles northeast of Santorini, one of the world’s most popular tourist islands.

The magma chamber was discovered using full-waveform inversion technology, which records ground motions and analyzes wave velocities near volcanoes. Magma chambers can be detected by a reduced velocity of seismic waves traveling beneath the seafloor, the study reported.

Michele Paulatto, a volcanologist at Imperial College London in England,  and second author of the study, said in a press release that “Full-waveform inversion is similar to a medical ultrasound. It uses sound waves to construct an image of the underground structure of a volcano,” to show a picture.

Kolumbo could potentially produce a highly explosive eruption. Scientists compare it to the recent eruption of Hunga Tonga, which last erupted in January 2022 and caused tsunami waves up to 66 feet high, the magazine noted.

In 2020 K.L. Konstantinou of the National Central University, Taiwan estimated that Kolumbo produced five major eruptions in the last 70,000 years, but that “an eruption in the near future is unlikely,” the new technique showing otherwise, said the Israeli newspaper Haaretz.

The scientific team said there was a regional hazard to other islands based on the imaging technology of full-waveform inversion, which, like medical ultrasound, uses sound waves to image hidden structures and that the molten rock in the chamber may be approaching a volume similar to that last eruption.