Italy's Volcanoes: The Cradle of Volcanology

Etna index

   
Geology Geological history Cones and craters
Eruptive characteristics Eruptions before 1971 Eruptions since 1971
Etna and Man References Web sites
Weather forecasts FAQ Latest news

Etna seen from Lipari

Splendid view of snow-covered Etna from the island of Lipari, about 100 km to the north, in April 1995

The morphology of Etna


Aerial views of Etna, around 1983
These spectacular photos are from the collection of Carmelo Sturiale (+1988), who worked as a volcanologist at the University of Catania since the late-1950's. They were taken during an overflight of Etna, probably between 1981 and 1983 (possibly at the beginning of the 1983 eruption) and show details of the morphology of the volcano, such as the summit area, the Valle del Bove, and the summit cone complex (which has changed considerably since the photos were taken). The photos were kindly made available by Giovanni Sturiale. Click on the thumbnails to see much larger versions of the photos.
Aerial view, 1983

Left: The upper 1000 m of Etna seen from east-southeast, with the southwestern rim of Valle del Bove in the left foreground. Click here to see an annotated large version of the photo: MSC=Main summit cone; NE=NE Crater; SE=SE Crater; M=Montagnola; C=Cisternazza (a pit crater formed in 1792); SG=Serra Giannicola.
Right: Looking east along the southern crest of the Valle del Bove (named "Schiena dell'Asino" which means "donkey's back"). The conspicuous cone in the foreground is Montagnola, a cone formed during a flank eruption in 1763.

Aerial view, 1983
Aerial view, 1983 Left: Summit cone complex seen from north-northeast. Click here to see an annotated large version of the photo: NE=NE Crater; V=Voragine; BN=Bocca Nuova; SE=SE Crater; M=Montagnola.
Right: Main summit cone and SE Crater seen from the east-southeast, with grayish ash being emitted from Bocca Nuova. The annotated large version of the photo shows the names of the features visible in the photo: '71=1971 "Observatory cone"; SE=SE Crater (note that at that time it was simply a large pit); '64=remainder of the 1964 cone complex in the summit crater; BN=Bocca Nuova; V=Voragine; NE=NE Crater.
Aerial view, 1983

Contrary to common belief, Mount Etna is not a simple shield or strato volcano. Its shape and structure are extremely asymmetric and complex, and a classification of the mountain on a morphological basis is nearly impossible. The reason for this complexity is that Etna did not grow as one single large cone, but as a succession of volcanic edifices most of which suffered partial collapse at least once during their lifetimes, and whose centers shifted from one place to another. Several calderas can still be discerned morphologically, the most impressive being the huge Valle del Bove (Valley of the oxen) on the eastern side of the volcano whose latest collapse episodes occurred only a few thousand years ago. Etna's morphology is further complicated by the presence of areas with more frequent eruptive activity, like the Northeast Rift which forms a distinct ridge dotted with eruptive cones and cut by numerous gaping fissures. Hundreds of minor pyroclastic cones are scattered all over the flanks of the mountain, some of which appear to be small volcanoes on their own, with edifice heights of several hundred meters, while many others are much smaller, with heights of only a few tens of meters. These were produced by flank eruptions, the most dangerous, and probably the best documented, type of activity at Etna in recent times.
At the summit of the volcano stands a complex of large cones which actually host the four summit craters. This peculiar family of craters, which are somehow connected but show a surprising degree of independence from each other, is a relatively recent feature. One hundred years ago, until 1911, there was one single large cone at the summit of Etna, that was truncated by the 500 m-diameter Central Crater. Two new craters, the Northeast and Southeast Craters, formed in 1911 and 1971, respectively, and have since built their own cones which rival the old central summit cone in size and height. In recent years the Southeast Crater has been particularly active and its growing cone now forms a prominent landmark at the summit of Etna. Viewed from south and southeast it actually seems higher than the central summit cone, but this is an effect of perspective; actually the summit of the Southeast Crater cone is still about 20 m lower than the highest point of the volcano.

Etna from NW

Left: Etna seen from the northwest. This view, taken from near the village of Maletto, shows the snow-clad edifice of the youngest structural unit of Etna, Mongibello. The cone visible at left is Monte Maletto, one of about 250 flank eruptive centers on the volcano.
Right: Etna from SSW and the 1669 eruption. Outcrop in the southwestern part of the 1669 lava flow, near the town of Misterbianco. The flow was erupted from a large flank cone, Monti Rossi, which is visible in the far right; this cone lies about 15 km from Etna's summit (visible in the left center). The major cone visible immediately to the right of the snow-covered summit area is Montagnola, a crater formed in 1763.

Etna from SSW
Cones near Nicolosi Left: Flank cones near Nicolosi. The southern and southeastern flanks are dotted with cinder cones produced by flank eruptions, some of which occurred during historic times. This view is from the summit of Monti Rossi (the main 1669 cinder cone), on the northwestern margin of Nicolosi, and shows five cones. The cone visible in the upper left center (it has three peaks) is Monte Arso, formed in the 15th century.
Right: Montagnola, a cone formed in 1763. The second of two flank eruptions in 1763 occurred on the upper southern rim of the Valle del Bove and built a large cinder cone named Montagnola. This eruption produced an unusually thick lava flow-field which can be seen as a ridge extending from the Montagnola crater to the right margin of the photo.
Montagnola
Montagnola Views of Montagnola from near the main summit cone. The views were taken from the summit of the "Observatory Cone" formed in 1971, lookking south. Left: The view during summer (September 1989). Right: Same view taken during the winter (April 1990). Note black lava flows extending from the foreground to near the base of Montagnola; most of these were erupted in 1971, but the right photo shows a very dark lava flow at left which is from the September 1989 eruptions of SE Crater. Montagnola

Seen from different directions, the shape of Etna shows striking variations, as can be seen on clear days during a roundtrip in the Circumetnea train or by car. From southeast, the view is more or less in line with the main axis of the Valle del Bove, and differs considerably from the Catania perspective. Here, until the summer of 2001, the mountain appeared quite symmetrical, culminating with the summit crater complex, and with two prominent peaks rising to the south and north, forming a peculiar pair of "shoulders" on the mountain sides. These are the Montagnola to the south and the Pizzi Deneri, which lie on the westernmost extensions of the south and north rims of the Valle del Bove, respectively. The 2001 and 2002-2003 eruptions have brought significant changes to this panorama. Three large pyroclastic cones were formed between the summit cones and the Montagnola and are plainly visible from southeast, and the shape of the volcano now appears much less symmetrical.
Seen from Catania to the SSE, the volcano appears fairly symmetrical in its upper portion but further downslope to the east the symmetry is broken by the irregular rims of the Valle del Bove, which culminate in the Pizzi Deneri to the north. Furthermore, the Montagnola, a large cone formed during a flank eruption in 1763, constitutes a prominent peak below the summit craters. The sizeable pyroclastic cones formed during the 2001 and 2002-2003 eruptions are now additional features on the upper south slope.
If the volcano is viewed from different places along the highway leading from Catania to Adrano to the northwest, its shape becomes increasingly asymmetrical, as the peak of the Montagnola begins to stand more and more to the right of the steep upper slopes and summit area - the gently sloping area that lay between the summit and the Montagnola until 2001 was known as the Piano del Lago (plain of the lake) and now hosts the three large cones formed during the 2001 and 2002-2003 eruptions. To the left (west), the rounded upper west flank gradually evolves into a fairly steep slope, whose base transforms into a gently sloping terrain dotted with numerous flank cones. Between Adrano and Bronte, further to the north on the west side of Etna, the shape of the volcano once more becomes more symmetrical as the irregular morphology of the Piano del Lago-Montagnola area disappears from view. Seen from west, the mountain essentially shows three main morphological units: the broad, bulky summit crater complex at the top, followed below by the steep upper western flank that is lined by numerous dark lava flows (many of these were erupted during an eruption at the Bocca Nuova summit crater in 1999). The lower portion of this flank is much flatter and densely forested; dozens of flank cones of different sizes and ages sit on this slope, of which the most recent two were formed in 1974.
Continuing the clockwise round trip from Bronte to Randazzo, the shape of Etna returns asymmetrical, with the upper west flank (now seen to the right) appearing once more rounded, while the northeastern flank to the left forms a gently sloping, straight line starting shortly below the Northeast Crater, which now dominates the summit outline. Flank cones are much less abundant on this side, but the voluminous lava flow-field of the 1614-1624 flank eruption becomes apparent, which consists of various terraces and rootless lava shields (formed around ephemeral vents at the ends of lava tubes). Eastward from Randazzo along the Alcantara river, the shape of the volcano once more turns symmetrical, but details begin to emerge on the Northeast Rift, which forms the slope to the left and consists of numerous cones and craters of different size and shape. The most prominent of these is Monte Nero, which formed during a flank eruption in 1646-1647. As the town of Linguaglossa is approached, the northeastern (left) flank of the mountain begins to show different elements. Below the summit craters to the left now appears the crest of the Serra delle Concazze that culminates at right in the Pizzi Deneri and constitutes the south rim of the Valle del Bove lying behind. The slope below the Serra delle Concazze is steep and cut by numerous valleys, some possibly of glacial origin. Below that slope, the flank of the volcano is sloping more regularly but is abruptly interrupted by the prominent ridge constituted by the Northeast Rift, where the large cone of Monte Nero is the most conspicuous feature.
Near Linguaglossa, the steep symmetrical cone of the Southeast Crater appears to the left of the summit, which still dominates the summit area of the volcano, and as the descent toward Piedimonte and then Fiumefreddo is made, the mountain once more obtains a highly asymmetrical shape. The irregular crest of the Serra delle Concazze to the left (east) is now visible over its full extent, while the right flank is dominated by the Northeast Rift. Driving south along the Ionian coast, the wide opening of the Valle del Bove becomes more and more evident, with its southern and northern crests forming irregular ridges. Higher upslope, the cones of the 2001 and 2002-2003 eruptions return to the view, until the roundtrip arrives to the north of Acireale, where the perspective is again in line with the long axis of the Valle del Bove.

This section includes two further pages where specific aspects of the Etnean morphology are discussed in more detail:

  • The Valle del Bove, a huge collapse depression on Etna's eastern flank. Here you will learn about the various hypotheses proposed to explain the origin of the Valle del Bove, including fascinating new findings.
  • The cones and craters of Etna. This will get you acquainted with the recent eruptive centers of Etna, on the flanks (where there are hundreds of pyroclastic cones) and the summit craters, which have an eventful history.

On this page there are many photographs depicting various morphological elements of Etna, such as lava flow features, and furthermore you will get a more graphical idea of what, until now, you have only seen in maps or in text descriptions. This chapter is the base of what will eventuarlly develop into "the Virtual Etna", which will allow you to click on any point on an Etna map to see photos and detailed maps of the chosen area.

Etna seen from Ionian Sea

Etna dominates the skyline of the city of Catania (in the foreground) in this photo taken from a ship off the Ionian coast in June 1997


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

Page set up on 22 April 1999, last modified on 8 February 2004
Hosted by VolcanoDiscovery