Etna Decade Volcano, Sicily, Italy
Lava flows spilling down the western side of Valle del Bove, seen from "Belvedere" on the evening of 3 March 1999
Updates 11-31 March 1999
The most recent updates
Etna news archive
25 March 1999
A brief period of improved weather yesterday (24 March) permitted good views of Etna and the site of the current eruption. Lava continues to flow into Valle del Bove, although less lava is visible at the surface than about two weeks ago. While a major flow issues from an ephemeral vent about half way down the western slope of Valle del Bove, several smaller flow lobes were visible on the crest of the Valle last night. The eruption is now going on since seven weeks and shows no signs of diminishing. The new surface flows above the rim of Valle del Bove were probably caused by a blockage of one of the main lava tubes and subsequent surface breakouts, a phenomenon often observed at Kilauea, Hawaii. Giuseppe Scarpinati (Italian correspondent of the Paris-based European Volcanological Association "L.A.V.E." and resident in Acireale with a commanding view of the mountain) reported that during a visit on the last weekend by a friend and "fairly accurate observer", no activity was observed in any of the two large summit craters, Bocca Nuova and Voragine. This observation confirms that all magma rising within the central conduit system of Etna is currently erupted from the fissure formed on 4 February.
23 March 1999
Poor weather has precluded observations of Etna's activity during the past week, and no information about the current progress of the effusive activity initiated on 4 February is available. During most of the time, the volcano has been shrouded in clouds, and during the few glimpses no morphological changes or changes to the activity at the summit craters were observed. The lava flow into Valle del Bove is still hot, but no nocturnal observations have been possible in order to ascertain if lava is still flowing. As soon as weather conditions permit a view of the volcano at night, new updates will be posted on this page. Late-March to early April is usually a period of unstable weather in Sicily and it may be difficult to observe Etna or climb to its summit during the next few weeks.
14 March 1999
Two days after the latest visit by Behncke and others, the eruptive fissure
and the area of flowing lava were again visited by geologists of the IGGUC (Behncke,
Monaco, Giampiccolo and Bianca) on the late afternoon of 13 March. Good weather
conditions and the ongoing effusive activity attracted hundreds of tourists,
and the area where lava appears at the surface and spills down into Valle del
Bove was overcrowded with curious spectators, photographers and volcanologists
from Italy and abroad. As for the effusive activity, there were only minor changes
as compared to the situation seen (with much less people around) two days earlier.
The southern lava flow breached on its southern side and numerous branches were
seen spilling over the rim of Valle del Bove. Nothing much had changed at the
northern lava flow as far as could be ascertained. The output was still as high
as 5 cubic meters per second, and this effusive eruptive episode that began
on 4 February is thus estimated to have produced more than 15 million cubic
meters of lava, an amount that would well fit a classification as a typical
"slow" flank eruption of Etna (Etnean flank eruptions are generally
classified into those with relatively low effusion rates, such as the 1983 and
1991-1993 eruptions, and high-effusion rate eruptions like those of 1981 or
What was certainly most impressing during the 13 March visit was the presence of countless people in the eruption area. Many of them were local mountain guides and volcanologists, including groups of Catania's Istituto Internazionale di Vulcanologia, of the University of Palermo, and from the UK. However, they were largely outweighed by the crowds of tourists who flocked around the skylights and effusive vents, and work was at times difficult amidst all these people. Although the ongoing eruption is not accompanied by any appreciable explosive activity in this period, non expert visitors to the area, if they are not accompanied by guides or volcanologists who know the place, risk to get injured while walking on the fresh lava fields, or to get burned near skylights and active flows.
|13 March 1999 photos|
|Photo 1. Boris Behncke watching a small lava flow issuing from an ephemeral vent near the rim of Valle del Bove (note gesture to protect the face from the heat emitted by the lava). Photo courtesy of Carmelo Monaco, IGGUC||Photo 2. A procession of tourists is moving to the site where lava is flowing (at left) into the Valle del Bove whose southern wall can be seen in the background||Photo 3. Tourists and volcanologists gathering on the rim of a skylight (a hole in the roof of a lava tube). On the left side of that skylight, hot gases rushed up from the lava, and observers risked to get burned|
|Photo 4. Lava flows spilling over the rim of Valle del Bove, a suggestive sight at nightfall||Photo 5. View from the "Belvedere" after sunset of the lava cascades on the wall of Valle del Bove||Photo 6. Lava flows spilling into the Valle del Bove, and the lights of the Taormina area in the background|
12 March 1999
A group of geologists (Boris Behncke, Mariangela
Porravecchio, Giuseppe Paradiso and Antonella Lentini - from left to right)
of the Istituto di Geologia e Geofisica of the University of Catania (IGGUC)
visited the eruptive fissure at the base of the SE Cone yesterday. Above the
rim of Valle del Bove, all lava was now flowing in tubes, and only a few skylights
indicated the course of the lava in this area. There are apparently two main
lava tubes about 30 m apart at the rim of Valle del Bove. The more southerly
tube ends just above the crest of the Valle where the lava appears at the surface
to form a braided stream, and two more ephemeral vents emit lava a little further
downslope. The northerly lava tube extends much further into the Valle, and
surface flows appear only half way down its western slope, at, say, 2500 m elevation.
The active flow fronts appear to be quite a bit above 2000 m elevation and the
southern edge of the lava field may extend further south than indicated on the
3 March map above. No activity has occurred at the hornitos in the uppermost
part of the fissure, but degassing is occurring from several incandescent fumaroles.
Geologists from Palermo University measured temperatures of about 1030 degrees
in one of these fumaroles.
There appeared to be little activity elsewhere although something that appeared to be a phreatic steam explosion from Bocca Nuova's southeastern vent area occurred at around 1300. It formed a convoluted clouds but contained little or no ash, and it produced no sound. When descending from the summit area at dark, no incandescence was visible at the summit craters.
|11 March 1999 photos|
|Photo 1. One of the largest hornitos in the upper part of the eruptive fissure, inactive since at least 10 days and crusted with sulfur. Height of the hornito is about 2.5 m. Effusive vent of 2 March is visible in the lower foreground.||Photo 2. Panoramic view of the main hornito cluster at the base of the SE Cone which is visible in the background. Note the 4 February fissure (steaming in its uppermost part) that extends from the summit of the SE Cone to its base.||Photo 3. Spectacular lava tube near the rim of Valle del Bove, with lava flowing at about 4-5 m depth. Note the wavy structures at the left margin of the flowing lava, possibly caused by some kind of turbulence in the flow.|
|Photo 4. Making ash-trays of lava: a mountain guide is using a kind of fork to pick a chunk of lava from a flow issuing from an ephemeral vent.||Photo 5. Another view of the guide picking lava for another ash tray.||Photo 6. The still-plastic lava is inserted into a semmingly archaic device that serves to shape it and to stamp the word "ETNA" and a small symbol of the volcano onto it.|
|Photo 7. Freshly produced ash trays of still incandescent lava are placed on the ground where they are slowly cooling. The full-size version of this image shows the symbol and "ETNA" stamped on the floor of the ash-tray.||Photo 8. Suggestive view at dusk of a skylight about 5 m long (from left to right) with lava flowing at about 5 m depth.||Photo 9. Lava flows spilling over the rim of Valle del Bove at dusk. Montagnola and, to the left of it, the southern rim of Valle del Bove (the "Schiena dell'Asino") are visible in the background. View is to the south.|
|Photo 10. Lava issuing from an ephemeral vent on the rim of Valle del Bove. Note the threads of lava crust extending gradually in the flow direction (to the left), thus forming the roof of an incipient new lava tube..||Photo 11. View eastwards into the Valle del Bove from its western rim, showing lava flows moving towards the Monti Centenari (visible in the upper right background).||Photo 12. At sunset, the view of the incandescent lava flows spilling into the Valle del Bove gets more and more suggestive. Montagnola and the "Schiena dell'Asino" in the middle background, and the Bay of Catania in the far left. View is to the south.|
|Photo 13. Lava cascading into the Valle del Bove, with the SE Cone in the background. View is to the northwest.||Photo 14. Yet another view of the lava flows on the rim of Valle del Bove, with Montagnola in the background.||Photo 15. Braided lava river, detail of the previous photo.|
|Photo 16. Lava issuing from ephemeral vent on the rim of Valle del Bove, flowing from lower left to upper right. Persons in the background give scale.||Photo 17. The main southern lava river on the rim of Valle del Bove as it gets darker and darker, and the lights of Catania in the background.||Photo 18. Same view as previous, but about ten minutes later, showing the scene at night. The lights in the far right are of the towns of Augusta and Siracusa, 60-80 km south of Etna.|
Page set up on 6 April 1999