Vulcano

Primordial Volcano

Vulcano, with its 22 sq km is the third largest island of the Aeolian archipelago after Lipari and Salina, and it entirely consists of volcanic rocks. The island, with its maximum height of 500 m asl represents only a small part of a major volcanic apparatus which extends under the sea for about 1 km deep. The island consists of five main volcanic complex.

Caldera del Piano

It is the oldest part of the island and it formed between 120,000 and 100,000 years ago. It is a cone formed by the lava flows, in prevalence scorias and pyroclastic materials. Originally the cone had to have a diameter at sea level of about 5 km and a height of the emerged part of about 800 - 1000 m.

After a violent explosive eruption, which occurred about 100,000 years ago, the top of the primordial cone has subsided, giving rise to a roughly circular depression (Caldera del Piano) with a diameter of about 2,5 km bounded by vertical walls of at least 300 m. This depression was subsequently filled by lava flows and to a lesser extent, from pyroclastic products which are the result of numerous eruptions occurred between 99,000 and 50,000 years ago.

Vulcanello

It is located in the northernmost sector of the island and it consists of a lava platform to which overlap three volcanic cones partially penetrated and lined up towards West-Northwest. Vulcanello was formed as an independent island, in 183 BC. In 1550 d.C. Vulcanello has joined to the main island after a violent explosive activity that formed the isthmus between the “Porto di Levante” (west port) and the “Porto di Ponente” (east port).

Caldera della Fossa

This is a sub-circular structure and is located to the north of the Caldera del Piano, in the middle of which stands the active volcanic apparatus of the summit of the Volcano. This cone formed as well after an overlapping of pyroclastic deposits which alternate with layers of lava flows expelled during eruptions began about 6,000 years ago and whose most recent episode dates back to 1888-90.

Lentia

This is a series of lava flows and stocks (domes) erupted 24,000 - 15,000 years ago, which form the north-western portion of the island. This complex lava was subsequently affected by a new collapse, which led to the formation of the “Caldera della Fossa”.
The village of Vulcano is located inside the depression of the “Caldera della Fossa” and is dominated by the homonym eruptive cone. Turning your back to the port, your eyes meet a steep wall formed by massive rocks of a reddish colour. They are the lavas flows and domes that constitute the complex of Lentia, erupted between 24,000 and 15,000 years ago. The composition of rhyolitic magma  that generated them, very rich in silica , gave to these lavas a high viscosity and therefore little ability to flow, thus leading to the formation of large accumulations taking the name of domes.
During cooling the thermal contraction produced the big cracks that cut the lava clusters, disposing to form a sort of rough circle. The cliff that cuts the domes and shows their most internal parts, is the result of the collapse from which  resulted the Caldera della Fossa.

The cone of the "Pit of the Volcano" has always had a fumarolic activity that produced a  deposition of sulphur, chloride and ammonium bromide, sodium and potassium, and sulphides of lead and bismuth, sulphates and borates. Before the 1888-90, some convicts of a penal colony were used in extraction of sulphur and alum deposited by ancient fumaroles also in the area of “Faraglione”, near the “Port of Levante” (east port), at that time an uninhabited area. During the following years fumarolic activity has significantly diminished in intensity,  a resurgence in the'20s, when the emission of steam and gas grew strongly in temperature, which reached 624 ° C in 1924. In the following decades the activity decreased again until the second half of the 70’s, when the crateric fumaroles had almost disappeared.
Since 1977 fumarolic activity has again taken place, causing the opening of small fractures at the edge of the crater, an increase in the flow of steam and gas and an increase in temperature, which arrived to almost 700°C in the early 90’s, before falling back to current values around 500°C. In recent years the fumaroles moved from the edge to the inside of the crater, whose visit is absolutely not recommended.