The 1989 SE Crater and ENE flank eruptions

One of the most spectacular eruptions at Etna during recent decades began in early September 1989, culminating in a series of violent lava fountaining episodes from Southeast Crater (SE Crater) that were followed by a flank eruption in the upper N part of Valle del Bove (called Valle del Leone), and, later, by more fountaining episodes from SE Crater. The main phase of the eruption occurred during the declining tourist season when there were still many observers around, and therefore it was very well observed. I was among those observers and thus lived the first major eruption of my life.
One of the main features of the 1989 eruption and associated geophysical events was the formation of a fracture system that extended several kilometers southeastwards from SE Crater, towards densely populated areas. Fortunately, no eruption occurred from this fracture system, but the development of similar fractures in the future could well culminate in an eruption.

1989 eruption photos by Giuseppe Scarpinati
The SE Crater in vigorous Strombolian eruption on the evening of 16 September 1989. Between 11 and 27 September, the SE Crater produced 14 episodes of paroxysmal eruptive activity, characterized by high lava fountains and voluminous lava emission. Between some of these episodes, Strombolian activity like that shown here occurred between some of the paroxysms.	A view of the SE Crater from the Torre del Filosofo mountain hut on 25 September 1989. Compared to what it is now (in early 2000), the cone around the crater was quite insignificant. A steaming crack is seen on the near flank of the cone, evidence of fracturing of the cone on its flanks during the later events of the series of paroxysmal eruptive episodes.	Lava flows produced by the eruptive episodes of the SE Crater (which is hidden by weather clouds in this photo taken on 25 September 1989) have flowed several kilometers towards the Piano del Lago (in the foreground), interrupting the dirt road which leads to the Torre del Filofoso building (seen on a hill in front of the fuming main summit cone, in the background).

Lava flows erupted from the SE Crater on 22 September 1989 have encircled the Torre del Filosofo mountain hut. One lava lobe has touched the NW corner of the building (right photo), but the wooden shack used during the summer season by the mountain guides has been miraculously left unharmed. Photos were taken on 25 September 1989.

1989 eruption photos by Boris Behncke
	Left: Eruptive episode from SE Crater on the morning of 26 September 1989, producing an eruption column 6 km high. This event was accompanied by lava emission from fractures on the southern and northeastern sides of the crater, and loud roaring sounds made windows vibrate in Nicolosi from where the photo was taken. Top right: Continuous ash emission from SE Crater on 29 September 1989, after the beginning of a flank eruption in Valle del Leone, northwest of Valle del Bove. This activity consisted of strong jets of ash and bombs every few seconds accompanied by muffled noises. Building at right base of eruptive plume is the Torre del Filosofo mountain hut. Bottom right: A close-up view of SE Crater from a point about 1 km to the south on 29 September 1989. A cock-tail shaped bomb and ash fountain is jetting from the crater
	Left: View from the southwestern rim of Valle del Bove ("Schiena dell'Asino") towards Etna's summit area with the erupting SE Crater. Strombolian bursts eject incandescent bombs to about 250 m high. Clouds over Valle del Bove at extreme right reflect glow from the flank eruption. Photo was taken at sunset on 29 September 1989. Right: Looking down from the "Belvedere", a panoramic point on the western rim of Valle del Bove, to the lava flow of the flank eruption (the eruptive vents were located in Valle del Leone and are not visible in this photo), on the evening of 28 September 1989.

Etna seen from the home of Giuseppe Scarpinati (the photographer of this image) on 28 September 1989. This is the second day of the flank eruption in the Valle del Leone, whose lava flow is visible at right. A dense ash plume is rising from the SE Crater, which continues to produce Strombolian activity, but no longer lava flows.

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