Can a cable listen to an underwater volcano? 🌋🌊

Near the Greek island of Santorini, an active volcano lies hidden beneath the sea. Scientists are now testing an unusual way to study it: a fiber-optic cable that can help detect tiny movements on the seafloor.

The volcano is called Kolumbo, and it sits about seven kilometers northeast of Santorini. Its underwater crater reaches a depth of around 500 meters and contains areas where hot fluids and gases escape through the seabed.

A cable with a surprising job

Fiber-optic cables are usually associated with fast internet. But they can also help scientists detect vibrations.

For the HYDROSENSE expedition, researchers plan to use a system called Geo-Sense with a 500-meter fiber-optic cable. The instrument sends laser light through the cable and measures changes in the returning light. Those changes can reveal disturbances along the cable.

The team wants to find out whether this method can help detect signals associated with volcanic activity, earthquakes and fluids moving beneath the seafloor.

A robot joins the mission

The cable won’t work alone. The team also plans to use a small remotely operated underwater robot, MiniROV, to inspect the area, record video and help create detailed maps of the volcano.

The expedition runs from October 30 to November 12, 2026. The technology is being tested; it has not been shown to predict an eruption. Researchers hope the information will improve understanding and future monitoring of underwater volcanoes.

It’s a reminder that engineering can give scientists new ways to study places they cannot easily visit—and even help them “listen” to the ocean floor. Image: AI-generated conceptual illustration.

Sources: MBARI HYDROSENSE expedition and expedition log.