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Monti De Fiore

The first and larger of the two pyroclastic cones formed during the January-March 1974 eruption on the west flank of Etna, Monte De Fiore I, seen from north. Lavas produced by the same eruption are in the foreground. Note irregular shape of the cone, and depression formed above lava source on near side (above the single tree). Another effusive vent forms a small knob on the south (right) base of the cone. The lower flank of the second cone, Monte De Fiore II, is seen at extreme right. Photo taken in mid-October 2002

The 1974 W flank eruption, its cones and lava flows


Following a series of earthquakes that were registered by the seismic network created after the 1971 eruption, a new vent became active on the afternoon of 30 January 1974 at about 1670 m elevation on the west flank of Mount Etna. This vent immediately became the site of strong explosive activity, and a cone began to grow rapidly. Lava was extruded from vents shifting frequently in shape and location, mostly at the base and on the flanks of the growing cone. This lava was seen to be unusually viscous for Etnean lavas, although at the same time it was rather mafic and virtually devoid of phenocrystals, which is unique in the recent history of the volcano. These peculiarities were due to the fact that this was an eccentric eruption - that is, a flank eruption not fed from the central conduits, as most other flank eruptions). Such eruptions are generally more explosive since the magma feeding them does not lose any of its gas content before erupting. The 1974 eruption was the only eccentric eruption during the 20th century.
The first eruptive phase of the 1974 eruption lasted from 30 January until 16 February, and the cone built up during this phase stood about 70 m above the former surface. Lavas had extended from as many as six effusive vents mostly south, southwest, north, and northwest, reaching a maximum length of 1.5 km from their sources. One peculiar flow extended over a short distance to the north; this flow is unusually thick (up to 10 m) and shows marked ogive structures on its surface. But lava did not only issue from these vents on the flank and base of the cone, it also oozed through the base of the cone, forming a steep-sided "collar" around the eastern base of the cone, which is up to 10 m high.
After 22 days of calm, a second crater became active about 200 m to the west of the earlier cone, at about 1650 m elevation. This crater also showed strong explosive activity, and lava flowed through an open breach in the western side of the growing cone, forming a field of overlapping lobes little more than 1 km long. The activity at this cone, which was named Monte De Fiore II, lasted until 29 March.
The volume of lava produced by this eruption was unusually small, amounting to 4.5 million m3 (2.4 million m3 of the first and 2.1 million m3 of the second phase). However, the amount of pyroclastics was relatively great in comparison, amounting to more than 3 million m3 (two-thirds of these were erupted during the first phase), testifying to the high degree of explosivity.
Today, the two cones of the Monti De Fiore remain largely barren, and only lichens have grown on their lavas. The remains of pine trees burned by the eruption thirty years ago are slowly rotting. The colorful landscape of the Monti De Fiore are one of the most popular attraction to local hikers, although to most people it is virtually unknown, and very few of the thousands of daily visitors to Etna get to know it. It is not easy to find the few, and insufficiently marked trails leading to the place. The best way to reach the Monti De Fiore is by car from Adrano to Monte Intraleo, and then on foot on the Forest Guard roads to Monti Nespole, Monte Leporello, and Monte Grosso, where a small, and largely overgrown path leads down to the Monti De Fiore. The return can be made starting southward from Monte De Fiore II (there is no footpath) in the direction of the Monti Nespole, but this includes about 150 m across lava from the 1974 eruption, which is not pleasant to walk on.

Maps of the 1974 lava flows

1974 lava flow map

Overview map of the location of the 1974 eruption area and the 1974 lava flows (shown in red color). Summit craters are in right central part of the map (NE = Northeast Crater; V = Voragine; BN = Bocca Nuova. The Southeast Crater was only a small collapse pit at the time of this eruption), and lava flows of the previous eruptions (after 1700) are shown in pink color, the dates of the most important of these flows are also displayed. Some of the names of older pyroclastic cones are shown as well. TDF = Torre del Filosofo

1974 lava flow map

More detail is visible in this map. The flows of the first and second phases of the eruption are distinguished, and older pyroclastic cones on the western flank of Etna are labeled

Photos of the 1974 eruption

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Left and center: Vigorous explosive activity at the actively building Monte De Fiore I during the first days of the 1974 eruption. These photos were taken by Giuseppe Scarpinati on 2 February 1974, three days after the beginning of the eruption
Right: Activity at Monte De Fiore II, early February 1974, photographed by Carmelo Sturiale. Note large breach on the flank of the cone

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Photos of the first phase of the 1974 eruption, taken by Renato Bernardini - now a researcher at the Medical Department of Catania University who at that time was a boy with an amateur camera. These images distinctly show the new cone (Monte De Fiore I, the first of two cones to grow during the eruption) built by Strombolian activity amidst a forest on the western flank of Etna.

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1974 eruption 1974 eruption 1974 eruption

1974 eruption

Early stage of the first phase of the eruption (early February 1974). These photos were taken by Carmelo Sturiale, volcanologist at the University of Catania (+1988), and they clearly show the strong explosivity of the eruption. Note the breach in the eastern crater rim of Monte De Fiore I visible in the second photo.
In the lower row, the first photo shows lava eating through a pine forest near Monte De Fiore I, the last three photos show the activity of the cone as night falls.

March 1974

A rare photograph of the second phase of the 1974 eruption (this took place between 11 and 29 March 1974), taken by Carmelo Sturiale looking eastwards. The cone built during this phase (Monte De Fiore II) is seen in mild explosive eruption, and the snow-covered bulk of Etna's cone is visible in the background, with the fuming main summit cone sitting on top of it. The reddish hue of the photo is due to to the ageing of the print.

March 1974

Another photograph of Monte De Fiore II in activity, taken in March 1974 by Carmelo Sturiale. This view is from the south-southwest, showing Monte De Fiore I (which grew during the first phase of the 1974 eruption) to the right of the active cone, and Etna's snow-covered main cone in the right background.



THE MONTI DE FIORE TODAY (photo gallery)

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THE 1974-1978 NE CRATER ERUPTIONS

Copyright © Boris Behncke, "Italy's Volcanoes: The Cradle of Volcanology"

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