Description
Vulcano island, origin of the term applied to all volcanoes in the world, is the southernmost of the Aeolian Islands and is located about 20 km from the northern coast of Sicily. The island, rising about 500 m a.s.l., from a depth of over 1000 m (Gabbianelli et al. 1991), was formed, together with Lipari and Salina, along a NNO-SSE oriented, lithospheric structure. Owing to this volcanic edifice’s frequent volcanic activity, the ancient Greeks supposed that the God of Fire, Hephaestus, worked in his forge inside the active cone. The island of Vulcano consists of three different volcanic edifices, partially destroyed by calderic collapses. The southern portion of the island consists of the “Primordial volcano”, truncated by the Piano caldera. To the north is the Lentia-Mastro Minico building, which was largely destroyed by the collapse of the Fossa caldera, about 14 ka ago. This caldera hosts La Fossa cone, formed in the last 5500 years. The northernmost part of the island is the Vulcanello peninsula, whose formation began with a submarine eruption in the 2nd century BC, leading to the birth of an island in the strait between Vulcano and Lipari. Repeated eruptions on this new island made it grow and, in the Middle Ages, it joined the main island of Vulcano. The last eruption at Vulcanello dates back to the 16th century. In recent centuries, however, the activity has been concentrated at the Fossa crater. An important eruptive cycle began in 1727, and in 1739 the “Pietre Cotte” rhyolite flow, the most recent effusive activity of Vulcano, was issued. The next 150 years, were characterized by sporadic explosive activity, which culminated in the latest eruption from Vulcano, which took place between August 2, 1888 and March 22, 1890. This eruption led to the introduction of the term “Vulcanian” activity, characterized by very strong explosions, which emit fragments of lava in an almost solid state. During the 1888-1890 eruption, numerous, major bread-crust bombs were launched as far as the area now occupied by the town of Vulcano Porto. Since the area was then uninhabited, there were no casualties or major damage, even if the fallout of pyroclastic material and the shock-wave caused by the strongest explosions, led to damage to buildings on the nearby island of Lipari. However, in the eventuality of an eruptive crisis, Vulcano Porto will be now seriously at risk. Since the latest eruption, Vulcano has been in a state of eruptive quiescence, with activity limited to fumaroles. The peculiarity of the quiescent La Fossa cone is the occurrence of “crises” characterized by strong increases of the temperature and output from fumaroles, as well as by chemical changes indicative of an increasing input of magmatic fluids (Granieri et al., 2006). The most recent of such episodes happened in 1985 and 2004.
Credits: Model description by Massimo Cantarero, as well as the photogrammetry processing and 3D model. Photos for processing are from Alfio Amantia – INGV Osservatorio Etneo.
The 3D model of the crater was generated after a helicopter survey flight performed on 25 June 2014, during which about 100 images of the entire Fossa crater were taken.
– References
- Gabbianelli G., Romagnoli C., Rossi P.L., Calanchi N. and Lucchini F. (1991): Submarine morphology and tectonics of Vulcano (Aeolian Islands, Southern Tyrrhenian Sea). Acta Vulcanologica, 1, 135-141.
- Granieri, D. and Carapezza, M. L. and Chiodini, G. and Avino, R. and Caliro, S. and Ranaldi, M. and Ricci, T. and Tarchini, LCorrelated increase in CO2 fumarolic content and diffuse emission from La Fossa crater (Vulcano, Italy): Evidence of volcanic unrest or increasing gas release from a stationary deep magma body? GEOPHYSICAL RESEARCH LETTERS, VOL. 33, L13316, doi:10.1029/2006GL026460, 2006