A hot surprise near Greece

Researchers from MARUM – Center for Marine Environmental Sciences, University of Bremen, were surprised to discover a large field of hydrothermal vents near Milos Island, Greece.

Hydrothermal vents are natural openings on the seafloor where hot, mineral-rich water escapes. They form when seawater sinks down through cracks in the ocean floor, is heated by hot rocks or magma below, and then rises back up again. As the water heats up and moves through the rock, it picks up minerals and gases along the way.

When this hot, mineral-filled water flows out of the vent and meets the cold ocean water, the minerals can settle and build up on the seabed.

The team identified three main vent zones, all lined up along cracks, or faults, in the Earth’s crust. These faults act like natural plumbing, allowing hot, gas-rich fluids to escape from below the seafloor. When researchers first saw the vents through cameras attached to remotely operated vehicles, they found bubbling fluids, shimmering water, and thick mats of microbes coating chimneys created from all those minerals that were brought up from beneath the surface.

Why it matters

Hydrothermal vents support unusual ecosystems and reveal how heat, gases, and chemicals move from inside the Earth into the ocean. Finding such an extensive vent system in shallow water makes Milos a natural open-air laboratory that could help scientists better understand volcanoes, hydrothermal systems, and tectonics.

Read the paper Structural control and depth clustering of extensive hydrothermal venting on the shelf of Milos Island (open access)