Eruptive vents and small cones built along the main segment of the 1923 eruptive fissure at the eastern base of Monte Nero, seen here in late May 2000 and looking downrift to the NNE. Persons on cone in the distance indicate scale

Mamma Etna's countless children
1923 eruptive fissures
NE flank, 15.028353° E, 37.807783° N (largest cone near Monte Nero)
Mean elevation: 1900 m

In June-July 1923, the Northeast Rift, which had been the site of frequent eruptions in the past, opened once more, only twelve years after another large eruption in nearly the same area. This eruption had been preceded by several weeks of intense activity at the Northeast Crater and thus represents a fine example of a flank eruption following increased summit activity, a scheme that has become more common since the second half of the 20th century.
A very complex system of new eruptive fissures became active with this new eruption. The main fissures formed in the area immediately around Monte Nero, a huge pyroclastic cone formed in 1646-1647. One fissure opened immediately uprift from that cone, then the feeder dike propagated directly towards Monte Nero and was split up into three branches, probably because the presence of the cone presented a structural obstacle to the propagating dike. One branch passed towards the west, where a small horseshoe-shaped cone was built up, a second branch passed right through Monte Nero and a small lava flow was erupted from the northeastern side of its cone, almost from the same site where lava had been emitted during the 1646-1647 eruption. The third and largest eruptive fissure opened at the eastern base of Monte Nero, and here a spectacular row of small spatter cones and hornitos was formed, while lava flowed in a broad river in the direction of Linguaglossa. This lava flow reached the western outskirts of that town and destroyed a few buildings; furthermore it buried a section of the Circumetnea railway and the nearby State Road. Never during its history had Linguaglossa been so close to destruction.
The eruptive vents of the 1923 eruption are among the most impressive and instructive volcanic features to be seen in the Monte Nero area. Fortunately the nearby eruption of October-November 2002 did not bury these sites, although new vents opened just a few hundred meters to the east (unfortunately they emitted lava flows that virtually obliterated the tourist facilities of Piano Provenzana). The main fissure at the eastern base of Monte Nero is almost in the same state as immediately after the 1923 eruption, with the exception that narrow footpaths are now leading around the countless vents and cones on the fissure. Some of the spatter cones reach heights of up to 10 m, most are much smaller, and there are numerous small vents, mere holes in the ground, sometimes only a few tens of centimeters wide but their bottom seems to lie at endless depth.
Like Monte Nero, I have visited the 1923 fissures on many occasions since early May 2000, often with groups of geology students for which the Monte Nero area serves as a phantastic laboratory in volcanology.

Left: uppermost portion of the 1923 fissure system, where a few relatively large craters have formed. Lava has spilled from the lower end of this fissure segment. The Northeast Crater at Etna's summit is seen in right background. Photo taken in late September 1999 Center: dark tongues of lava erupted during the 1923 eruption are seen on the middle portion of the Northeast Rift in this view taken from Monte Timparossa in mid-August 2002 Right: among the many volcanic features seen in this photograph, taken from the south rim of the Monte Nero crater in late May 2000, the small vents in the center of the image are of the 1923 eruption. The larger crater to the left, named Monte Ponte di Ferro, formed during the same eruption that built up Monte Nero, in 1646-1647

These photos show some of the countless cones and miniature craters on the main 1923 eruptive fissure as they appeared in late May 2000. Individual descriptions are not necessary here - but note persons standing on the tallest of these cones in the lower center and right images

More photos of the main 1923 fissure, taken in late May 2001 (left and center) and late May 2000 (right). Photograph at right is a view into one of the smaller vents, whose open conduit (only about 30 cm wide) is still open to an undetermined depth

Excursionists and students discovering the vents on the main 1923 fissure one after one, in late May 2001 (left and center) and in late May 2000 (right)

Left: eruptions of Etna can result in features of incredibly different size. The huge cone in the background, of which only a part can be seen in this image, is Monte Nero, formed in 1646-1647, while the small dark cone lying at its base formed in 1923. Photograph taken early May 2000 Center: this view is from the southern termination of the main 1923 eruptive fissure to the south, showing lavas erupted from fissures located higher upslope during the same eruption in center and left portions of the image. Photo taken late May 2000 Right: a snow-filled lava flow-channel of the 1923 eruption at the southeast base of Monte Nero, fed from vents lying higher upslope. Photo taken in early May 2000

Left: collapsed shallow lava tube, formed during the 1923 eruption, near southeast base of Monte Nero. Note relatively smooth and often ropy surface of lava within the collapse depression. Photo taken early May 2000 Center: looking uprift along the 1923 eruptive fissure to the southwest of Monte Nero, during poor weather conditions in early May 2000 Right: same segment of the 1923 eruptive fissure system as in previous photo but slighly higher uprift and during excellent weather in late April 2002. In the left foreground, a small crater formed during the 1646-1647 Monte Nero eruption was filled by 1923 lava. Small pyroclastic edifices formed on the eruptive fissure are visible in right half of the image, and the dark tongue of lava passing through the saddle between the two hills in the left background is also of the 1923 eruption

Left and center: small cone (about 5-8 m tall) formed in 1923 in the lower part of the eruptive fissure south of Monte Nero, seen from Monte Ponte di Ferro (a cone formed in 1646-1647 that lies further east) Right: effusive vent on the western side of a row of 1923 spatter cones (at right) formed immediately to the southwest of Monte Nero (which is seen in the background). Photos taken in late April 2002

Left: looking across eruptive vents of 1923 to the southwest of Monte Nero (center-right background) toward a horseshoe-shaped pyroclastic cone lying at the WSW base of Monte Nero, late April 2002 Center: horseshoe-shaped 1923 pyroclastic cone on WSW base of Monte Nero, seen from south rim of the crater of Monte Nero in late May 2000. This cone is approximately 15 m tall Right: hikers walking across 1923 lava immediately below the small horseshoe-shaped cone seen in previous photograph, early May 2000

Continue to Monte Rosso

Return to the Etna flank cone index

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