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WARNING:
Access to the summit area is VERY DANGEROUS.
Violent eruptive episodes are occurring about twice per day
at the Southeast Crater, and heavy showers of tephra (including
clasts tens of centimeters in diameter) may occur up to several
kilometers away. Besides this, weather conditions are often
unstable. The winter brings frequent snow storms and clouds,
and one gets easily lost due to the lack of points of reference
once there is a thick snow cover. Excursions should be made
only with the mountain guides who can be contacted at the cable
car (near the Rifugio Sapienza) on the southern side of Etna,
or at the hotel "Le Betulle" at Piano Provenzana,
on the northern side.
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16
February 2000 update.
The twenty-seventh paroxysmal eruptive episode of the Southeast Crater
since 26 January occurred shortly after 1600 h (local time=GMT+1)
on 16 February, little more than nine hours after its predecessor.
As usual, the culminating phase of the event was very short-lived
(less than ten minutes) and consisted of violent lava fountaining
and emission of lava flows on the southern (and possibly northern)
flank of the SE Crater cone. An eruption column consisting mainly
of vapor but containing ash in its lower part rose at least 5 km above
the summit of Etna and then drifted to the SE. As of nightfall on
16 February, lava continued to flow from a new vent at the SSE base
of the SE Crater cone.
On the same day at about 0700 h, the SE Crater had produced its previous
paroxysm. Like its predecessors it produced tall lava fountains, minor
lava flows and a spectacular eruption column. According to Giuseppe
Scarpinati who observed the event from his home in Acireale, the culminating
phase was of short duration - maybe less than 10 minutes, and affected
mostly the southern side of the SE Crater cone.
The previous paroxysm had occurred just after 1800 h (local time=GMT+1)
on 15 February. The event was perfectly visible from Catania and other
locations south, east and north of the volcano and produced huge lava
fountains, possibly higher than 500 m, lava flows (mainly on the S
side of the SE Crater cone), and an eruption column that rose several
kilometers into the sky. The culminating phase apparently lasted somewhat
longer than those of previous episodes, but by 1830 all explosive
activity had ended. Only at the end of the most intense activity the
vents on the N flank of the cone reactivated, producing a minor lava
flow. The repose period between this paroxysm and the previous one
was one of the longest (26 hours) of the past two weeks.
Marco Fulle (Astronomical Observatory of Trieste, Italy), Tom Pfeiffer
(University of Arhus, Denmark), British cameraman David Bryant and
others were at Torre del Filosofo when the paroxysm occurred. Fulle
reported that the first evidence of the imminent paroxysm was an increase
in the gas output at the crater, shortly before 1800 h. Within a few
minutes, Strombolian bursts became visible at the summit vent of the
SE Crater cone, and lava began to flow from a vent high on the S flank.
The Strombolian activity continued for several minutes, followed by
a powerful incandescent blast that sent ballistic bombs far beyond
the base of the cone, and large, still molten lumps of lava fell at
Torre del Filosofo, forcing the group of observers to seek shelter
on the SE side of the building. However, from then on all the fallout
was blown to the E by strong wind, and no further pyroclastics fell
at Torre del Filosofo.
The most impressing feature of the activity, according to Fulle, was
the height of the fountains jetting from the SE Crater. In aggreement
with estimates made by Behncke (from Catania) and Scarpinati (from
Acireale), the fountain height was at least 500 m. The activity
appears to have been more intense in this paroxysm (and also in the
previous one) than during earlier paroxysmal episodes.
15
February 2000 update.
The saga of paroxysmal eruptive episodes at Etna's Southeast Crater
(SE Crater) is continuing. It appears now that since the late evening
of Saturday 12 February there have been four eruptive episodes: one
around midnight on 12-13 February, one at around noon on 13 February,
one at about 0330 h (local time=GMT+1) on 14 February, and the latest
one so far (as of on 15 February, shortly after midnight) at 1600
h on the 14th. The event on the early morning of 14 February was observed
by Giuseppe Scarpinati from his home in Acireale (north of Catania)
and apparently resembled strikingly the spectacular eruptive episode
of the evening of 11 February (see photos above), but the volume of
lava produced by that paroxysm may have been smaller.
The paroxysm of the afternoon of 14 February was again witnessed by
Boris Behncke (Dipartimento di Scienze Geologiche, University of Catania)
and Giuseppe Scarpinati at very close quarters. They had climbed to
the summit area during the early afternoon in spite of highly uncertain
weather conditions and were rewarded by the sudden vanishing of the
cloud cover that had veiled the upper part of Etna since the forenoon.
Expecting a possible paroxysm at the SE Crater, they chose not to
go to the Torre del Filosofo mountain hut - which was right downwind
of the crater - but instead reached a spatter rampart formed in 1991
and now half-buried in recent lavas, which stands about 900 m SE of
the crater.
Just a few minutes after their arrival in that place, the gas output
from the effusive vents on the N flank of the SE Crater cone began
to increase, and soon sprays of lava were seen to rise a few tens
of meters from the same area. A few minutes later - at exactly 1600
h - a broad, dull red fountain roared from these vents to a height
of about 100 m, and gas emissions increased rapidly in a number of
spots on the upper N flank. Small rockfalls occurred on the southeastern
flank of the cone, possibly caused by seismicity (although no tremors
were felt at the observation post of Behncke and Scarpinati).
At 1605 the summit area of the cone was veiled in gas, but soon after
a huge jet of glowing bombs was seen rising from the summit, forming
a rapidly expanding eruption column. Shortly thereafter, a densely
tephra-charged, cauliflower-shaped plume burst obliquely upwards from
the S side of the summit of the SE Crater cone. At the same time,
incandescent pyroclastics were seen falling from the column to far
beyond the base of the cone, but none hit the area from where Behncke
and Scarpinati were filming and photographing the activity. It must
be noted here that both were equipped with hard hats, gas masks, and
they were ready to retire away from the fallout area in case the fallout
front approached in their direction. The escape route was easy to
walk on and would have permitted rapid movement away from the danger
zone.
Instead, the curtain of falling ash and scoriae rapidly extended southwards,
towards Torre del Filosofo, and one man, who had previously approached
the lava field near the base of the SE Crater cone, was seen running
for shelter at the building - he was later found to have escaped unharmed.
The continuous loud rumbling of the fountains mixed with the pattering
noise of large clasts impacting the snow cover near Torre del Filosofo.
While much of the SE Crater cone was hidden from view by dust clouds
generated by the continuous rain of pyroclastics onto its flanks,
lava could be seen flowing down the S flank in a broad stream a few
minutes after the onset of the paroxysmal activity.
At about 1620, the activity began to wane, and the only vent to produce
lava fountains was that at the summit of the SE Crater cone. Shortly
thereafter, the loud roaring noise faded, and the fountain was replaced
by dense ash puffs.
Behncke and Scarpinati explored the area around Torre del Filosofo
shortly after the cessation of the activity; this area had been in
the main axis of the pyroclastic fallout. Large scoriae formed a near
continuous deposit, and many of the clasts were 15-20 cm in diameter
or even larger. All consisted of highly inflated scoriae, there were
no dense bombs even closer to the base of the SE Crater cone. When
descending from Torre del Filosofo on the late afternoon, Behncke
and Scarpinati found clasts with diameters of up to 10 cm at a distance
of 4 km from the SE Crater, near the upper station of the cable car.
Scoria fragments several centimeters across were found near the Rifugio
Sapienza, and a continuous sheet of lapilli extended from there southwards
to as far as the suburbs of Catania.
Lava continued to advance slowly at the southern base of the SE Crater
cone at about 1700 h when the area was examined by Behncke and Scarpinati.
The flows had not extended as far as some of the earlier flows, and
they had apparently been fed from vents high on the S flank of the
SE Crater cone. Lava continued to ooze from these vents, producing
frequent incandescent rockfalls.
The observations made during the paroxysm of the afternoon of 14 February
confirm once more the typical evolution of such an event. Activity
commonly starts at the northern effusive vents, where lava output
increases, followed by mild spattering which then rapidly develops
into a broad lava fountain. The activity then progressively moves
upslope on the northern flank of the SE Crater cone and culminates
with the appearance of several tall lava fountains from vents at and
near the summit. This climactic stage lasts approximately 10 minutes
and is followed by a rapid diminuition of the activity, passing into
ash emissions and a few isolated jets of lava, before all eruptive
phenomena cease altogether. In some events, this last stage is characterized
by one or more violent explosions that eject large lumps of lava all
over the cone.
The cone of the SE Crater has grown visibly since the last summit
visit by Behncke and Scarpinati on 8 February, and a deep notch is
present in the southern and northern crater rims. Lava has fanned
out at the southern base of the cone, and between eruptive episodes
lava apparently oozes slowly from vents on the upper S flank of the
cone.
It cannot be said how long this series of paroxysmal eruptive episodes
will continue, and what will occur after that. For the moment the
eruptive activity of Etna is limited to the summit area, and the flanks
below the SE Crater cone show no evidence of structural instability
which might lead to a flank eruption. Etna produces almost continuous,
and often vigorous, eruptive activity from all four summit craters
- at times simultaneously, at times only at one or two craters - since
the summer of 1995. This is a fairly long period, but between 1955
and 1971 there was near continuous summit activity and no flank eruption,
so that the present activity may continue to be restricted to the
summit area for still some time, maybe years.
13
February 2000 update.
Weather conditions have worsened over this weekend, seriously hampering
visual observations of the activity in the summit area of Etna, and
in this moment it is difficult to follow the course of events. Furthermore,
the tempo of the eruptive activity at the Southeast Crater (SE Crater)
has apparently accelerated once more, with three eruptive episodes
in 12 hours between the late evening of 11 February and the forenoon
of 12 February. The eruptive paroxysm, which occurred at about 2200
h (local time=GMT+1) on 11 February, was featured in spectacular video
footage which has been shown in all major news services of the world.
As a result, this page received more than 800 hits on 12 February,
unprecedented in the history of "Italy's Volcanoes".
After the paroxysm on the evening of 11 February, the SE Crater went
through its shortest repose interval so far, 6 hours, and then erupted
again at around 0400 h on 12 February, in a manner much similar to
the previous episode. Yet another eruptive episode occurred after
a similarly short repose interval at about 1000 h on 12 February.
Nothing is known about the activity since then, but it is assumed
that one or more paroxysmal episodes have occurred.
Lava flowing
from vents on the N flank of the SE Crater cone (which is seen immediately
above the church tower) on 8 February 2000. Photo was probably taken
shortly before or after an eruptive episode at the SE Crater from
the village of Zafferana by press photographer Fabrizio Villa/Associated
Press
Several
other web pages covering the October-November 1999 eruptions of the
Bocca Nuova have recently been posted; these contain photos and movie
clips of some of the most spectacular moments of that period.
A
photo gallery covering the period September-November 1999 (with photos
by Boris Behncke and Giuseppe Scarpinati)
Photos
of the eruptive activity, 26-31 October 1999, by Tom Pfeiffer (University
of Arhus, Denmark)
Photos
by Marco Fulle, 17-23 October 1999, at Stromboli On-line - Marco at
his best
Very
impressive video clips, taken by Roberto Carniel on 17-23 October
1999, at Stromboli On-line
Photos
by Juerg Alean, of 1 November 1999, at Stromboli On-line
Video
clips, taken by Juerg Alean on 1 November 1999, at Stromboli On-line
A
page by Charles Rivière, France, with many photos of the summer
and autumn of 1999 (in French)
visitors counted since 12 February 1999
(This page has received an incredible 4362
hits during the week of 24-30 October 1999. 4430
hits were counted the week after. However, this is nothing compared
to the more than 1000 visitors daily in mid-February 2000)
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Page set up on 27 May 1997, last modified
on 18 February 2000
