In June of 2023, Becky (my wife) and I, found ourselves in Catania, Sicily from booking a Mediteranian. There, we booked a tour that took us to the sides of Mount Etna.

Imaged below, northeast of Catania on Sicily’s east coast is Etna, (Europe’s highest active volcano).

Mount Etna is young, at just one million years old, but it more than makes up for its youth with its explosive nature, (It has been erupting constantly for the past half million years).

Pictured above, Etna is an enormous mountain, covering an area larger than London in England, and dominates the entire island, though the height of it’s crater depend on the current volcanic activity. Currently, it is about 3360m high with natural scrub vegetation at its base; cool forest of oak, chestnut, and birch on the way to the top; and black moon-like landscape.

Imaged above, The tour only took us to the Rifugio Sapienza, (1900m elevation) and gave us only 30 minutes to explore. A cable car would of transported us to the summit of the Montagnola vent (2500m elev.), but Mount Etna was rather active while we were there, so they were not running.

Eruptions are fed from a reservoir of molten lava below the mountain that is estimated to be 30 km long and 4 km deep. A recent study indicates as the source area of the magma that feeds Etna a zone located about 30 km below the Hyblean-Maltese escarpment.

Eruptions of Etna follow multiple patterns. Most occur at the summit, where there are five distinct craters – the Northeast Crater, the Voragine, the Bocca Nuova, and two at the Southeast Crater Complex.

Pictured below, other eruptions occur on the flanks, which have more than 300 vents ranging in size from small holes in the ground to large craters hundreds of meters across. Summit eruptions can be highly explosive and spectacular but rarely threaten the inhabited areas around the volcano, (pictured above).

Since the year AD 1600, at least 60 flank eruptions and countless summit eruptions have occurred; nearly half of these have happened since the start of the 20th century. Since 2000, Etna has had four flank eruptions – in 2001, 2002–2003, 2004–2005, and 2008–2009.

The main force that formed the earth’s crust in this area are still responsible for the geological phenomena that continue to be recorded, such as earthquakes and volcanic events, (image below).

Imaged above and below, the intense tectonic or volcanic activity in Sicily or in the nearby area, is very complex to understand. The difficulty of interpretation lies in the fact that all the geodynamic phenomena occurring at the same time. Here, the thrust which generates the continental collision between the African and the European plate coexists, only a few kilometers away, with the stretching produced by the opening of the Tyrrhenian basin, (called theCalabro-Peloritan Arc) .

Imaged above, the contiguity of two adjacent zones of contemporaneous extension and compression, the inversion of extensional stress regimes registered in recent epochs and their overlapping evidenced in many areas, contribute to making the geodynamics of the central Mediterranean complex, (that includes the presence of different volcanic activities).

Imaged above, studies correlate the Etnean magmatism with the upwelling asthenosphere along the western boundary of the Ionian crust in subduction, and locate the Mount Etna on a large normal fault system extending from the north to the Aeolian islands, known as STEP fault system. However, Mount Etna is also located above a portion of Earth’s crust characterized by a transform fault system (similar to transcurrent faults) shifted westwards, from which would derive a volcanism very similar to that of a continental rift.

Activity in the Etnean area began about 500,000 years ago with the emission of tholeiitic magmas in a submarine and coastal environment that crop out on the coast to the north of Catania and was followed at around 300,000 years ago, by another episode of tholeiitic volcanism in the southwest sector of Etna. Beginning about 170,000 years ago, mafic alkaline magmas were emitted to form several eruptive centers and possibly the first major Etnean edifice, before the magmas became more evolved, leading to more explosive volcanism and the construction of a succession of volcanic edifices with alternating pyroclastic deposits, these are called Trifoglietto deposits.

Another series of major volcanic edifices grew, and partially were destroyed, by caldera collapse, during the Mongibello stage which is commonly subdivided into the Ancient and Recent Mongibello. The result of this eventful history is a highly complex edifice whose morphology is that of an asymmetric shield volcano topped by a stratocone and whose eastern flank hosts the Valle del Bove, a vast caldera depression formed during successive collapse events beginning during the late Trifoglietto stage and continuing through the Holocene. The activity of Etna during the past few thousand years has been characterized by lava emission and Strombolian activity, punctuated at times by more explosive episodes from the summit craters.

The recent significant history for Etna started on 11 March 1669 and produced lava flows that destroyed at least 10 villages on its southern flank before reaching the city walls of the town of Catania five weeks later, on 15 April. A study on the damage and fatalities caused by eruptions of Etna in historical times reveals that only 77 human deaths are attributable with certainty to eruptions of Etna, most recently in 1987 when two tourists were killed by a sudden explosion near the summit.

Pictured above, the middle southern flank of Etna is has some classic examples of Etnean fissure eruptions with eruptive cones aligned on it, due to frequent eruptions on what is considered the “south rift zone” of the volcano.

Montagnola, the peak forming the skyline, is a large pyroclastic cone formed during the summer 1763 eruption; its lava flows formed a peculiar ridge visible in the image shown above.

Three years later, another eruption built the Monti Calcarazzi crater row whose uppermost cone is visible in the upper left of the photo above.

Pictured above, in 1892, a six-month long eruption led to the formation of yet another crater row, the Monti Silvestri, from the largest of which the photo was taken on June of 2023. Another 1892 crater is visible in the right center.

Non-withstanding the frequent eruptions in this area (another one occurred in 2001), the largest complex of tourist facilities (including the Rifugio Sapienza and the base station of the cable car) has developed immediately to the west of the Monti Silvestri, (pictured below).