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Earth of fire

Actualité volcanique, Article de fond sur étude de volcan, tectonique, récits et photos de voyage

The Tyrrhenian basin forms the deepest part of the Mediterranean Sea , with the Tyrrhenian pit to a depth of 3,800 meters. It was caused by a geological process involving African and Eurasian tectonic plates , which began there 10 million years and is contemporary of the formation of the Apennine Mountains .


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Volcanism of the Tirreno Sea (green) - Volcanoes of the Aeolian arc (red) - Doc. amicidelleterra

Besides the Marsili submarine volcano , other major volcanoes emerge from the central Tyrrhenian plain : the Vavilov , the Magnaghi and many lesser known , including the Palinuro, the Glaucus , the Eolo, the Sisyphus , and the Enarete .
Vavilov , Marsili and Magnaghi were discovered in 1950 and named after the geologists have revealed.

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The submarine volcanoes of the Tirreno Sea ( 1-9 ) and the Sicily Channel ( 10-13 ) - Doc. Protezione Civile - Rischio vulcanico / Volcani Sottomarini .

The Vavilov emerges from the seabed at 3,600 meters and rises until it reaches 684 meters below the sea level. This large building, 30 km x 15 km and 350-400 km3 , can be divided into two parts , according to four dives of the submersible Cyana :
- From its base at 1500 m depth , it consists of thick layers of basaltic flows.
- Above 1500m depth , smaller flows emitted by the central volcano, and others through vents aligned NS . Lavas forming the upper parts are dated from 100,000 to 400,000 years.
Other observations suggest a phase of subaerial terminal construction, followed by a subsidence of the basin to more than 500 m. depth in the Quaternary.

Vavilov lavas are very close to OIB - Oceanic Island Basalts . Vavilov appears as an independent structure of the oceanic crust that supports , and does not represent a dorsal-related oceanic accretion.

The Palinuro seamount emerges from nearly 3,000 m depth up to 73 m. under the sea surface, on a fault system oriented EO . It is topped by a shoe-horse caldera. Lavas of the top are dated from the Pleistocene. Petrochemicals is roughly identical to that of the Aeolian arc , and interpreted as generated by the subduction of the eastern Mediterranean under the Calabrian arc .

A layer of marine ash , radiocarbon dated to 9,990 years ago , is similar chemically and stratigraphically to two other layers of ash on land south of Italy, and correlated to the activity of Palinuro seamount ( Siani et al . 2004)

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Position on submarine volcanoes of the Tirreno Sea compared to the Aeolian arc (in red)

The submarine volcanoes Eolo, Enarete and Sisyphus are aligned NW-SE , west of the Aeolian arc and are high of a thousand meters. Eolo is distinguished from others by a flat top.

Alcione volcano and its twin, the Lametini are located between the alignment Palinuro - Glabro and the Aeolian arc . These volcanoes have a conical shape, and the surrounding fund exceeds one thousand meters.

 

 

Sources:

- Protezione Civile – Rischio vulcanico / Volcani sottomarini - link

- Structural framework of the Tyrrhenian Sea unveiled by seafloor

morphology - Struttura del Mar Tirreno svelata dalla morfologia del fondale - M.P.Marini & F.Gamberi

- Geomagnetism and age study of Tyrhenian seamounts - O.Faggion & al.

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