Bold claim: Milos now anchors a new chapter in marine science, revealing an unexpectedly large network of hydrothermal vents off this Aegean island.
Three principal vent clusters emerge along active fault lines that cross the Milos shelf: Aghia Kiriaki, Paleochori–Thiorychia, and Vani. These sites lie within a tectonically active zone linked to the Milos Gulf–Fyriplaka graben, a broad depression that has lowered the seafloor to depths reaching about 230 meters. The tight coincidence of vent fields with these fault structures demonstrates that tectonic activity critically shapes where hydrothermal venting occurs.
We never anticipated encountering such an extensive gas-flare field off Milos, remarks Solveig I. Bühring, senior author and MARUM – Centre for Marine Environmental Sciences, University of Bremen, who led expedition M192 that discovered the vents. “When the ROV revealed the vents, we were struck by their variety and striking visuals—from shimmering, boiling discharges to thick microbial mats coating the chimneys.”
Paraskevi Nomikou of the National and Kapodistrian University of Athens, the study’s first author, notes that the spatial arrangement of vent clusters aligns closely with the island’s tectonic framework:
“Our data show clearly that the gas flares trace the major fault systems surrounding Milos. Different fault zones influence distinct vent clusters, especially at junctions where several faults converge. These tectonic structures dictate how and where hydrothermal fluids reach the seafloor.”
The work highlights how ongoing geological processes and active faulting have molded the evolution of Milos’s vent fields, positioning the island as a premier natural laboratory in the Mediterranean for studying the relationships among tectonics, volcanism, and hydrothermal activity.
The findings also inform the MARUM-based Cluster of Excellence “The Ocean Floor – Earth’s Uncharted Interface.” A follow-up expedition is planned to Milos, the Kolumbo submarine volcano off Santorini, and Nisyros. This research reflects a strong collaboration among Greek and German institutions, including the National and Kapodistrian University of Athens, MARUM – University of Bremen, Friedrich-Alexander-Universität Erlangen-Nürnberg, ICBM – Institute for Chemistry and Biology of the Marine Environment Oldenburg, and Constructor University Bremen.
Would Milos’s active faulting and hydrothermal systems provoke new debates about the limits of deep-sea ecosystems or strategies for engineering exploration in tectonically dynamic regions?
