Gelfiser crater and lava flow on Pantelleria (photo by G. De Astis, 2014)
The basaltic scoria cones of the Cuddie Rosse (with some associated lava flows), from the Holocene (photo by G. De Astis, 2014)
Location and maximum height: Strait of Sicily, 36.77°N, 12.02°E; Montagna Grande = 836 m above sea level
Total area of the island: ≈84 km2
Volcano type: Caldera with monogenic centers
Main types of eruptions: phreatomagmatic, effusive, Strombolian, Plinian
Prevailing phenomena: hydrothermal emissions, seismicity.
Beginning of eruptive activity: < 330-325.000 years
Last eruption: 1891
Activity state: quiescent
Alert level: Basic
Pantelleria is a volcanic island located in the Strait of Sicily - in particular along the continental rift between Sicily and Tunisia (Rift di Pantelleria) - and represents the emerged part of a much larger volcanic structure made up of lava and pyroclastic deposits of variable composition (from alkaline basalts to rhyolites, with those typical compositional terms of the island which are the pantellerites), with a marked bimodal character. Also including the submerged part, the volcanic apparatus rises from the seabed by about 1400 m. Although located in a geodynamic context characterized by the collision between two plates – the Eurasian and the African – Pantelleria owes its formation to the presence of an extensional tectonics. The island consists largely of a mosaic of overlapping eruptive centres, which have grown within an approximately 28 km2 caldera ("Caldera dei Cinque Denti") which in turn formed within an older one caldera (“La Vecchia", ≈ 42 km2). The formation of the younger Caldera is linked to high-energy explosive eruptions which deposited the Green Tufo of Pantelleria, now outcropping in a large part of the island.
The eruptive history of the island is long and the sub-aerial volcanism has a duration of over 300000 years, ending at an unspecified age between 4000 and 5000 years ago. There are no known volcanic activities in historical times on the emerged part of the island but there is evidence of two small basaltic submarine eruptions 4-5 km north-west of Pantelleria in 1831 and 1891 (ie shoal or Foerstner volcano), accompanied by seismicity and fumarolic activity on the island, as well as two episodes of uplift: up to 0.8 m along the north-eastern coast of the island (May-June 1890) and up to 0.55 m (in October 1891). The last eruption began on October 17 with the launch of incandescent lava fragments, visible both from the island and from the Tunisian coasts, and lasted until October 25. This eruptive episode, and the geology of the island in general, suggest that the volcanism has progressively shifted towards the NW. The rates of ground deformation, temperatures and gas emissions (H2Ovap., CO2 and H2S) recorded in the last 15 years are in agreement with the presence of an active hydrothermal system and a superficial magma chamber (≈ 4 km deep ) which would be cooling and in a state of deflation.
From prehistory to the Middle Ages, and initially due to the presence of the precious obsidian, many populations have come and gone on the island. Among these, in 835 AD, the Arabs who called her Bent al-Ryon, daughter of the wind, and who have left many traces in the island vocabulary (cuddia= hill; gebel= mountain).