Santorini’s Underwater Volcano: The Unusual Activities

Scientists have turned to cutting-edge technology to study Santorini’s underwater volcano, Kolumbo, as seismic activity in the region increases. A team from the National Technical University of Athens (NTUA), in collaboration with the National and Kapodistrian University of Athens (NKUA) and other research institutions, has been closely monitoring changes beneath the sea’s surface to better understand what’s happening below.

Using autonomous underwater robots, researchers have gathered crucial data that shows how the volcanic environment is changing. These robotic explorers—known as ROVs (Remotely Operated Vehicles) and Gliders—can dive deep into the ocean, collecting information for days at a time without human intervention.

What’s Going On Underwater?

Santorini is well known for its dramatic volcanic history, and scientists keep a close watch on Kolumbo, an active submarine volcano located just off the island’s coast. While there’s no immediate danger, recent research suggests that the area is experiencing significant underwater changes, possibly linked to increased seismic activity.

On Sunday, 2 February, a team of experts led by Professor K. Karantzalos and Dr. Evi Nomikou conducted deep-sea measurements, diving 500 metres below the surface to collect data from the volcano’s hydrothermal vents—natural openings that release hot, mineral-rich water.

By comparing these new readings with previous measurements taken in October 2024, scientists have confirmed major changes in the water, including:

✅ Increased turbidity (cloudiness of the water) by 25%, likely caused by volcanic activity stirring up sediments.

✅ Rising temperatures: Water that was once warm only at 500 metres depth is now heating up at 400 metres.

✅ Changes in water composition: Scientists observed shifts in the water’s chemistry 120 metres higher than in previous studies, meaning a huge volume of water—over 120 million tonnes—has been affected.

✅ Radiation levels tripling near the vents: The presence of radon, a naturally occurring radioactive gas, has significantly increased.

What Does This Mean? Should We Be Worried?

Before you start picturing lava eruptions under the sea, experts do not believe an immediate disaster is unfolding. However, these findings highlight that Kolumbo’s activity is shifting, and researchers need to keep a close eye on it.

Volcanologists and marine scientists will continue to monitor the area, using their high-tech underwater robots to track changes in real-time. Their mission? To detect early warning signs and understand how underwater volcanoes impact their surroundings.

Santorini’s beauty may be shaped by its volcanic past, but it’s also a reminder that nature is always in motion. While residents and visitors don’t need to worry just yet, the scientific community will remain vigilant, ensuring that if anything unusual happens, they’ll be the first to know.