Tyrrhenian Sea

Lore & Background

The Tyrrhenian Sea is a back-arc basin that formed due to the rollback of the Calabrian slab towards South-East during the Neogene. Episodes of fast and slow trench retreat formed first the Vavilov basin and then the Marsili basin. Submarine volcanoes and the active volcano Mount Stromboli formed because trench retreat produces extension in the overriding plate, allowing the mantle to rise and partially melt; magmatism is also affected by fluids released from the slab.

The International Hydrographic Organization defines the sea's limits through lines in the Strait of Messina, Strait of Bonifacio, and from Cape Lilibeo to Cape Teulada. The Tyrrhenian Basin is divided into the Vavilov plain and the Marsili plain, separated by the undersea ridge known as the Issel Bridge, after Arturo Issel.

Within the sea at a depth of 1,000 metres is the Caprera Canyon. An exploration by The One Ocean Foundation revealed colonies of rare sponges, corals, and numerous fish species, many endangered or at risk. The canyon's biology is currently at risk as of 17 November 2025 due to increased travel-based pollution and bottom trawling. The foundation is pursuing multiple layers of protection not currently provided for this area.

Reader's Guide

The Tyrrhenian Sea holds significance as a named body of water since antiquity, its name derived from the Etruscans, a pre-Roman civilization of central Italy. Geologically, it is a back-arc basin shaped by the collision of the African and Eurasian Plates, featuring deep basins, submarine volcanoes, and active volcanic islands like Stromboli. Its maximum depth of 3,785 metres makes it one of the deeper Mediterranean basins. The sea's ports—including Naples, Palermo, Civitavecchia (the port of Rome), Salerno, Trapani, Gioia Tauro, and Bastia in Corsica—have long served as maritime hubs. The Caprera Canyon, discovered by The One Ocean Foundation, highlights the sea's ecological richness and vulnerability, hosting rare sponges, corals, and endangered fish species. As of November 2025, this canyon faces threats from pollution and bottom trawling, with conservation efforts underway. The Tyrrhenian Sea also features in Greek mythology, where cliffs above it housed the four winds kept by Aeolus: Mistral, Libeccio, Sirocco, and Ostro.

Did You Know?

• The Tyrrhenian Sea's name comes from the Tyrrhenian people, identified with the Etruscans, first mentioned by Hesiod in the 8th century BC.
• The sea's maximum depth is 3,785 metres (12,418 ft).
• The Caprera Canyon, at a depth of 1,000 metres, contains rare sponges, corals, and numerous fish species, many endangered or at risk.
• The Tyrrhenian Basin is divided into the Vavilov plain and the Marsili plain, separated by the Issel Bridge undersea ridge.