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WARNING:
Access to the summit area is again VERY
DANGEROUS. Explosive activity at the Bocca
Nuova is frequently ejecting bombs far beyond the crater rims,
most notably on its N, NW, W and SW sides. It is still officially
forbidden to go beyond 2700 m elevation on the S flank. Tourists
should make excursions only with the mountain guides. Besides
this, weather conditions are often unstable. Strong wind, snow
or rain and clouds are occuring frequently in the summit area,
even during the summer, and one can get easily lost. The mountain
guides can be contacted at the cable car (near the Rifugio Sapienza)
on the southern side of Etna (phone: 095-914141), or (during
the summer) at the hotel "Le Betulle" at Piano Provenzana,
on the northern side (phone: 095-643430).
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PHOTOS OF THE 14 JUNE 2000 PAROXYSM
AT THE SE CRATER
SOUNDS AND MOVIE CLIPS OF THE
24 JUNE 2000 PAROXYSM AT THE SE CRATER
11 October 2000 update.
Vigorous eruptive activity is continuing at the Bocca Nuova, with
strong Strombolian explosions that frequently eject bombs far beyond
the crater rims. Observations of the activity were made during a summit
visit by Behncke (his 99th visit to the summit craters) on 10 October.
Eruptive activity is presently occurring within the "bottomless
pit" in the NW part of the Bocca Nuova, which has shown little
activity since the end of the October-November 1999 eruption from
the Bocca Nuova. During Behncke's last visit, on 27 September, mild
Strombolian activity had occurred at the second vent in the Bocca
Nuova, in the E part of the crater, informally named "1964 vent"
(a small cone had built in the same spot during a vigorous 1964 summit
eruption, but subsequent collapse of the Bocca Nuova had destroyed
this cone). This vent was found to be only strongly degassing on 10
October.
Mild Strombolian activity within the NW vent was continuous and punctuated
by frequent stronger explosions. The mild, "background"
activity, which produced a persistent "whooshing", surf-like
sound, only rarely ejected bombs to the lip of the vent. Stronger
explosions, however, were followed by sprays of bombs - some of them
up to 1 m across - which rose tens, at times hundreds of meters above
the rim of the vent. While most ejections were vertical, and the bombs
dropped back into the active pit, quite a few ejections had remarkably
low angles, and bombs were scattered over the surroundings of the
pit up to 300 m away. Most of the floor of the Bocca Nuova around
the active pit was littered with bombs, none smaller than 15 cm, and
some larger than 1 m. Bombs were furthermore found on the W slope
of the main summit cone, near a small footpath which has developed
in recent months across the October-November 1999 lava field, and
to the N of the crater. Many of these bombs were still hot to the
touch; one had incandescent cracks. One fresh bomb about 20 cm in
diameter was found E of the Bocca Nuova, on the platform of the former
Central Crater, which overlooks the SE Crater cone. This indicates
that access to the Bocca Nuova, which was relatively easy for much
of the past 11 months, has again become highly dangerous, but the
danger zone also extends several hundred meters beyond the crater
rims.
After nightfall the activity was spectacular to observe. There was
a continuous fluctuating glow at the vent, which was reflected from
the gas plume coming from it. Incandescent ejections came by no means
regularly, but were clustered at intervals of about 5-10 minutes.
Each series of ejections would culminate with one or more particularly
strong bursts, some of which were almost noiseless while others were
preceded or accompanied by very loud, ground-shaking detonations.
In some cases such detonations were preceded by a rapidly increasing
glow within the vent - this is evidence that the detonations were
caused by bursting bubbles of lava, similar to those observed in June
1998 at the Voragine (see July 1998 link in "archived updates"
at left).
Of the three other summit craters, two were observed directly during
the 10 October visit. The Voragine was emitting gas from its two vents
(the central one and the smaller one to the SW of it); observation
after nightfall revealed no incandescence at either vent. The SE Crater
was seen from the platform to the SE of the Bocca Nuova and showed
no signs of activity. The NE Crater was not visited, but mountain
guides reported that deep-seated explosive activity was continuing
deep within its active pit.
The activity observed at the Bocca Nuova is very similar to that of
one year ago, which preceded the spectacular outflow of lava from
that crater onto the W flank. During the period 5-16 October, explosive
(Strombolian) activity was followed by (or alternating with) Hawaiian-style
lava fountaining. Explosive activity observed by Behncke on 6 October
1999 was almost identical in style and intensity to that observed
one year and four days later. If the present activity continues, the
active pit may be rapidly filled and overflow, probably to the W like
one year ago. The rim of the active pit is lowest on its S side, and
lava would first cover the flat ground in the S part of the Bocca
Nuova before overflowing on the low W side. The activity may also
be expected to shift from the NW pit to the E (1964) vent and back
or to occur at both simultaneously. For those who liked last year's
spectacular Bocca Nuova lava overflows, this new activity looks quite
promising.
5 October 2000 update.
Eruptive activity at the Bocca Nuova has increased notably in the
past few days.
On the morning of 3 October, dense emissions of black ash began at
the E vent of the Bocca Nuova shortly after 0800 h and continued intermittently
for the next two hours, before clouds veiled the summit. At the same
time gas emissions were noted at the SE Crater summit vent. For the
next 24 hours cloud cover prevented visual observations for most of
the time. During the early morning hours of 5 October (before sunrise),
forest guard personnel being on fire watch on the W flank of the volcano
(near Monte Intraleo) noted incandescent ejections at the Bocca Nuova,
and at around 0730 h numerous observers in towns on the S and SE flanks
of Etna observed vigorous emissions of dark ash from the same crater.
Clouds then covered the summit area again, but between 0930 and 1030
a dense brownish ash plume could be seen trailing toward NW, and a
dense, white gas plume was rising above the weather clouds, when Boris
Behncke (Dipartimento di Scienze Geologiche, University of Catania)
drove towards the town of Nicolosi on the S flank. When Behncke and
a group of students and researchers from Geomar research institute
(Kiel, Germany) made an excursion to the W flank of the volcano, occasional
breaks in the cloud cover permitted a spectacular view of a dense
yellowish-gray plume rising vigorously from the summit area to a height
of about 500-800 m; the summit itself was hidden behind cloud. Bad
weather prevented visual observations at nightfall on 5 October, but
it is assumed that some eruptive activity is continuing.
Mild Strombolian activity began early last week and was observed directly
by Behncke and Dutch geologists on 27 September. The source of this
activity was at the E vent of the Bocca Nuova, which lies almost exactly
in the same position as a small crater that erupted in 1964 in what
was then the Central Crater of Etna. The local mountain guides refer
to this vent as the "1964 crater", and in future updates
on this site this vent will be named "1964 vent" to better
distinguish it from the large pit that lies in the NW part of the
Bocca Nuova (corresponding exactly to the position of the Bocca Nuova
during the 1970s and early 1980s).
Little is known about activity elsewhere at the summit craters, but
Charles Rivière reports on his
web site that during a 29 September visit, deep seated Strombolian
activity occurred both at the 1964 Bocca Nuova vent and at the NE
Crater.
29 September 2000 update.
True magmatic activity has resumed earlier this week at the E vent
of the Bocca Nuova. During a summit visit by Boris Behncke and a group
of geologists from The Netherlands on 27 September, mild Strombolian
explosions occurred every few minutes at that vent, ejecting bombs
and scoriae up to 50 m above the vent rim. It seems that most if not
all ejecta fell back into the vent. Many of these explosions were
followed by billowing clouds of grayish ash.
Local mountain guides reported that until about 24 September, all
activity in the Bocca Nuova had consisted of ash emissions, similar
to those described in the previous update below, and no bomb ejections
were noted. However, degassing at the two open vents in the Voragine
was said to have been stronger during the week ending on 24 September
than during the days after that date.
Very deep seated activity is also occurring in the NE Crater, and
the noise caused by this activity has increased notably during the
past week. During the 27 September summit visit, loud roaring sounds,
often lasting up to 15 seconds, were well audible at the Voragine
and in quiet moments they could be heard even at the hut of the mountain
guides of Piano Provenzana, located about 1 km W of the NE Crater.
Visual observations, however, did not reveal any ejections of solid
material, and no incandescence could be seen at the floor of the active
pit of the NE Crater.
The SE Crater, when seen from the E rim of the Voragine on 27 September,
was completely quiet. There were no gas emissions, neither at the
summit vent of the crater, nor at the fissure on the N flank of the
SE Crater cone.
20 September 2000 update.
Activity at Etna's summit craters has consisted, in the past two weeks,
of near continuous emissions of ash from the Bocca Nuova (mostly from
its eastern vent area), and strong degassing at the Voragine and the
NE Crater. During calm weather the ash rose as an impressive dark
column to several hundred meters above the summit. On some occasions,
light ash falls occurred in downwind areas, mostly on the E and SE
flanks of the volcano. Little fresh magma appears to be involved in
this activity, since most of the ash is altered, and probably derives
from the conduit walls where collapse is occurring frequently.
However, some explosive activity seems to take place at the summit
craters. People living on the E flank of the volcano reported frequent
"detonations" during the past few days, and there are unconfirmed
reports about an increase of the activity at the NE Crater.
10 September 2000 update.
For the first time in nearly two weeks it seems that some kind of
eruptive activity is taking place at the summit craters of Etna. This
activity has become evident as the cloud cover, which had hovered
over the mountain for two days (and brought the first fresh snow fall
of the forthcoming winter on the summit of the volcano), lifted shortly
before sunset on 10 September.
As of 1900 h this evening, a dense column of dark gray to black ash
rose from the eastern vent of the Bocca Nuova. This is clearly different
from the minor, brief emissions from the same vent during the past
few weeks, which produced small plumes of reddish or brown color.
The present ash emission is much more forceful and continuous, and
the color of the column indicates the possible presence of fresh magmatic
material, rather than altered material from the conduit walls. However,
as darkness fell, no glow could be observed. It can thus be concluded
that no true eruption is occurring at the Bocca Nuova, but the level
of activity is much elevated with respect to the preceding period.
The summit craters were relatively quiet when visited by Boris Behncke
on Monday 4 September (exactly one year after the great paroxysm at
the Voragine, which dropped large amounts of lapilli on towns and
villages on the E flank of Etna). However, observations were seriously
hampered by a very strong wind, weather clouds and dense gas plumes
emitted mostly from the Voragine. Mountain guides remarked that during
the previous days the pressure of the gas emissions from the Voragine
and the E vent of the Bocca Nuova had shown a distinct increase, and
there was possibly some deep-seated explosive activity in the latter
vent.
The SE Crater has remained perfectly quiet since its last eruptive
episode on the morning of 29 August, even the fumaroles that had been
very active during the days prior to its reactivation on 26 August,
have only emitted small quantities of vapor.
Several
other web pages covering the recent and ongoing eruptions of the Southeast
Crater are now available; these contain photos and movie clips of
some of the most spectacular moments of that period.
Etna
in 2000 - a list of all paroxysms at the SE Crater since 26 January
and photos (this site)
Extremely
spectacular video clips, taken by British cameraman and film maker
David Bryant on 15 February 2000
At
"Italy's Volcanoes" -
At Stromboli On-line
An
interview with Boris Behncke, made in late February 2000 by a BBC
team
and a video
clip (RealPlayer)
Photos
of the eruptive activity, 15-23 February 2000, by Tom Pfeiffer (University
of Arhus, Denmark)
Photos
of an eruptive episode on 13 February 2000, posted on the web site
of the Association Volcanologique Européenne, Paris, France
Photos
of the 15 February 2000 paroxysm of the SE Crater, by Thorsten Boeckel,
Germany
Photos
by Marco Fulle, 15-20 February 2000, at Stromboli On-line - very high
quality, as usual
Charles
Rivière's Etna home page, with many photos and video clips
(the most recent of the paroxysm of 5 May 2000), frequent updates,
and other, highly interesting items (in French and English)
