The Mediterranean, a body of water that has long been explored and mapped, has revealed a surprising secret: an active volcanic structure lurking beneath the waves. This discovery, made by a team of scientists aboard the research vessel METEOR, has shed new light on the region's geological history and the potential risks it poses to coastal infrastructure.
The structure, named Actea, is one of six volcanoes discovered during the M191 SUAVE expedition, which aimed to map the Sicily Channel, a busy shipping lane off the southwestern coast of Sicily. The team used advanced technology, including a multibeam echosounder and a magnetometer, to uncover three volcanic centers, each at least six kilometers wide and 150 meters high, entirely absent from existing geological models.
This finding is particularly intriguing because it challenges the accuracy of predictive bathymetry and highlights the complexity of volcanism in passive continental rifts. The western Sicily Channel, in particular, is a zone of pronounced crustal extension where volcanic forms cluster tightly along extensional faults, making it a difficult area to study without high-resolution mapping.
Actea, the closest volcano to the shore, is a cause for concern. Its summit rises to just 34 meters below sea level, shallower than many popular diving spots. The volcano shows signs of magmatic reactivation, with a substantial, recently emplaced lava flow, and bubbles streaming from its craters, which could indicate biogenic activity or hydrothermal circulation.
The Mediterranean region has a history of volcanic activity, as evidenced by the sudden appearance of Ferdinandea, a volcanic island that emerged in 1831 and sank just a year later. This patch of the Mediterranean has already demonstrated its capacity for surprise, and the discovery of Actea only adds to the region's potential hazards.
The study's findings have significant implications for assessing volcanic risk in heavily populated coastal zones. The risk extends to infrastructure, including communication cables and gas pipelines that cross the seafloor. The revised tectono-magmatic framework proposed by the team lays the foundation for future geochronological and geochemical campaigns, helping to protect against the hazards posed by these newly discovered volcanic structures.
The Mediterranean, with its millions of ferry passengers and hundreds of daily flights, is a busy and vital region. The fact that its depths are only now receiving serious high-resolution mapping highlights the vast unknowns that still exist on our planet, even in areas that have been extensively studied.
