SIGNS OF UNREST AT ETNA

Ash emission from the summit area of Mount Etna on the morning of 7 April 2003. Note snow-covered landscape in foreground. Summit area is hidden by light-colored weather clouds below dark ask plume. Photograph is from the 8 April 2003 issue of the newspaper "La Sicilia"

The latest update is below this line

28 April 2003 update. Eruptive activity at Mount Etna has been at low levels in recent weeks but sporadic ash emissions have occurred from the Bocca Nuova and the Northeast Crater; these emissions were presumably phreatomagmatic and ejected mainly old rock fragments. Somewhat more sustained ash emissions started during the afternoon of 28 April at the Northeast Crater; a dense grayish-brown plume was blown down the upper eastern slope of the volcano by a strong wind. Seismic activity is low and indicates no imminent major eruptive activity. However, it is likely that the summit craters will gradually return active over the next weeks to months; it is an open question whether this will continue for some time or whether it will be soon followed by a new flank eruption.

8 April 2003 update. Signs of a gradual reawakening of Mount Etna are becoming more abundant. Over the past few weeks, fumarolic emissions from the summit crater have apparently become denser and sometimes they were mixed with small amounts of ash. Fumaroles near the summit of the Southeast Crater have become more conspicuous, and during the first days of April, profuse steaming was also visible at the "Levantino", a small satellite cone on the north-northeastern flank of the Southeast Crater cone, which formed in the spring of 2001. On the forenoon of 7 April, dark ash was emitted from the summit area (see photo at top of this page), but inclement weather rendered observations difficult (Sicily, like all of Italy, is suffering from extremely bad and cold weather since late March, and Etna has been rarely visible since then). In a report of the local newspaper "La Sicilia", Sandro Bonaccorso, director of the Catania section of the Istituto Nazionale di Geofisica e Vulcanologia, is cited as saying that the activity is "absolutely normal and the situation is stable. There is no unusual seismicity and the tremor level is low. The ash emissions are probably caused by collapse within the summit craters. At present, there are no signs of an impending new eruption."
Over the past few decades, Etna has often recharged rapidly even after major flank eruptions. Magma reappeared within the summit craters 10 months after the end of the 2001 eruption, but on several earlier occasions during the 1980s, only two or three months passed between the end of a flank eruption and renewed summit activity. The current signs of unrest and heating of the summit craters might be a precursor of eruptive activity at the summit in the near future (weeks to months), which is what everybody would prefer to a new flank eruption. The increased fumarolic activity at the Southeast Crater and its "Levantino" satellite vent is the most intriguing of these signs: should this crater be the first to reawaken seriously, this might bring a new series of lava fountains like in 2000-2001. Such events are extremely spectacular but do not represent a significant threat to human property and infrastructures (except for short-lived tephra falls).
Following the destruction of the two access routes from south and north during the 2002-2003 eruption, the summit area of the volcano can be presently reached only with enormous effort, and the severe winter this year has rendered the situation still more difficult. Reconstruction of tourist facilities and access routes is planned in both areas but the latest surge of bad weather has so far prevented any work. Etna might be waking up, but it will be very difficult to watch this reawakening at close range.

12 March 2003 update. The post-eruptive quiet of Mount Etna continues, with practically nothing indicating an imminent resumption of eruptive activity. Yet the current slumber of the volcano is somewhat unquiet. From time to time the flanks of the volcano are shaken by small earthquakes, as on 9 March, when the southeastern flank was affected by several minor tremors. Another detail that might be significant is that over the past week, the snow which had abundantly fallen on the mountain a few weeks ago rapidly melted on the Southeast Crater. In addition, several fumaroles have appeared high on the cone of the Southeast Crater, which were not evident a few days ago. Visitors to the summit area heard explosions sounds coming from the Bocca Nuova around 9 March. A few isolated emissions of ash occurred during the past week from the Bocca Nuova and/or the Northeast Crater.
What does all this mean? First of all, all these phenomena have been observed also some time after the 2001 eruption, and on many earlier occasions after major eruptive activity. They indicate that magma is probably moving at depth within the volcano, but not necessarily that it is near the surface. And surely enough they testify that Etna is one of the most active volcanoes on Earth, which can only rarely be seen completely inactive.

27 February 2003 update. No news is good news, and there's virtually no news to report from Mount Etna, generally known to be one of the most active volcanoes on Earth. Since the seismicity and related ground rupturing at the Pernicana Fault in mid-February (see previous update), the volcano has been quiet volcanically and seismically, except for a few minor earthquakes in various sectors of the mountain. The latest of these occurred on 26 February 2003 (see the web site of the Istituto Nazionale di Geofisica e Vulcanologia, INGV) After the times of heat it's now the time of cold and wet: in January and February 2003 the Catania area received the heaviest rainfalls in more than 80 years (which is good news for Sicily) and temperatures have remained consistently below the monthly averages. This means that an enormous amount of snow has fallen on Etna. This is bad news to those who have lost the two skiing areas on the southern and northeastern flanks of the volcano during the eruptions of 2001 and 2002-2003. This would have been a marvellous skiing season.
But very likely, unnoticed so far, the process of recharging of Etna's magmatic plumbing system has already begun. If we look back at the past 30 years or little more, we see that after many flank eruptions the volcano was back to life within a few months. Following the 2001 eruption, it took 10 months to see incandescent magma in the summit craters again. If the volcano shows a similar behaviour in the future, the signs of recharging will probably be picked up by the dense network of monitoring instruments maintained by the INGV. Then there might be a new period of summit activity, like the one during the months prior to the latest (2002-2003) flank eruption. But this must not be necessarily the case. A new batch of ascending magma may also bypass the summit craters and directly intrude into the flank of the volcano; this has occurred, for example, in 1983. The chance that the next flank eruption will again affect one of the areas where the most recent flank eruptions have occurred is quite high. This is no good news.

13 February 2003 update. Sixteen days after the end of its latest eruption Mount Etna is again showing signs of unrest, although it is unlikely that these are indicative of renewed eruptive activity. Starting early on 12 February, a series of ten earthquakes occurred on the northeastern flank of the volcano, in the same area that had been affected by vigorous seismicity and ground deformation before and during the initial phase of the latest eruption. The strongest of the new earthquakes occurred at 0632 on 13 February (see the report of the Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania); it had a Md of 3.8 and the focal depth was 1.65 km. This means that this was a fairly shallow earthquake, and it was strongly felt by the owners of the "Ragabo" mountain hut, where light structural damage occurred. Near to this building (which narrowly escaped destruction by the lava flow from the Northeast Rift eruption in late October-early November 2002) ground fracturing was observed, which testify to a renewed displacement along the well-known Pernicana Fault. This east-west trending fault is believed to constitute the northern boundary of the unstable sector on the eastern flank of Mount Etna, which undergoes periodic slip toward the Ionian Sea to the east (similar movements are observed on the southern flank of Kilauea volcano, Hawaii). A major slip occurred at the beginning of the 2002-2003 eruption, which was accompanied by vigorous seismicity along the Pernicana Fault and at other faults on the eastern side of Etna. Witnesses of the latest earthquakes described the event as "the same thing that has occurred in last autumn". It is not very likely that the new unrest is related to magma movement, simply because the 2002-2003 eruption has drained much of the shallow plumbing system and no recharging of the central conduits has so far been observed (see the latest weekly report of the INGV, in PDF format).

3 February 2003 update (corrected 6 February 2003). Peace reigns again at Mount Etna, a little more than three (not four) months after one of its most significant eruptions in recent time began simultaneously on its northeastern and southern flanks. The volcano has fallen dormant, to the great relief of all those who live around it but also those who work on it (eruptions are not only spectacular to watch but also mean a lot of stress). According to the 29 January 2003 bulletin of the Istituto Nazionale di Geofisica e Vulcanologia (Sezione di Catania), volcanic tremor, which is a good indicator of eruptive activity, declined markedly on the evening of 28 January, and on the next morning no eruptive activity nor flowing lava were observed at the large pyroclastic cone on the upper southern flank. The final extent of the multilobate lava field formed below this cone since mid-November is shown on a composite map provided by the INGV-Catania.
Mount Etna is quiet again, and this morning was visible with a thick cover of freshly fallen snow, which melted only on the two huge, and still hot, cones formed on the upper southern flank. It is likely that for at least several months there will be no eruptive activity at this volcano, then there might be a resumption of mild activity at the summit craters and some time later, within a few years at best, a new flank eruption.

10 January 2003 update. What began as the 2002 eruption of Mount Etna is now the 2002-2003 eruption of this volcano, because as of 10 January, mild eruptive activity is still continuing at the huge pyroclastic cone on the upper southern flank of the volcano. This cone, whose growth began at an elevation of around 2750 m, has undergone slight growth during the past few weeks and is now much more than 150 m high. Lava continues to issue from a vent on its southern base to feed relatively minor flows to the southwest.

A summary of the 2002-2003 eruption

Piano Provenzana - a requiem

The 2002 eruption of Mount Etna is now featured on more and more web sites. The two principal sources of information (updates, photographs, and other graphic material) are:

The "official" Etna 2002 eruption web site at the Catania section of the National Institute of Geophysics and Volcanology (INGV) (in Italian)

Charles Rivière's Etna home page, with frequent updates and photos (in French)

Like in 2001, Lisetta Giacomelli and Roberto Scandone of the University of Roma 3 have created an incredibly informative and well-illustrated web page, which unfortunately is only available in Italian:

Eruzione dell'Etna 2002

Furthermore there are two web cams pointed on the southern flank of Etna, which can be accessed at the web site of:

Davide Corsaro, of the Hotel Corsaro, located at nearly 2000 m elevation on the southern flank of Etna

Two further web cams, located at Riposto (east-northeast of Etna) show a wide-angle view and a close-up of the volcano; these are provided by:

Albanet.com

Alain Melchior presents interesting digital models of the lava flows of the 2002 eruption and has numerous captures from Italian television news of the eruption

Eruption 2002 de l'Etna (du 26/10/2002 au ?)

One could expect some high-quality photography of the eruption at "Stromboli On-Line", and Marco Fulle's photos do fulfill all expectations...

The 2002 eruption of Etna at Stromboli On-Line

The same is true for Tom Pfeiffer's photos, which are among the most spectacular of the 2002 eruption so far available - Tom was lucky to be at Etna on the evening of 27 October and photograph the most spectacular phases of activity on the Northeast Rift:

www.decadevolcano.com

This is a relatively poorly known site, created in 2000, which has photos and spectacular video clips of the 2002 eruption (and of the activity in 2000 and 2001 as well):

Etna2000.com by Simone Genovese

Another web site that has escaped attention thus far, but deserves to be visited (good photos and movie clips, including one of the spectacular explosive eruption at the Voragine on 22 July 1998):

Malosito/Geoarchive by Marco Busetta

Very spectacular photos of the still-erupting crater at 2750 m elevation on the southern flank (seen from the Torre del Filosofo area) plus a nice map of the upper southern flank of Etna are available on

Thorsten Boeckel's web site

No less spectacular, the view of the eruption from the International Space Station (NASA):

The eruption seen from space on 30 October 2002

...and, of course, there are photos, updates and video clips at

www.vulcanoetna.com

Much information (in Italian) is offered by the Catania-based newspaper

La Sicilia

visitors counted since 12 February 1999
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