WARNING: Although
the 2002 eruption is continuing at only one single vent
on the upper southern flank of Etna (about 2750 m), and
all activity on the Northeast Rift has ended, access to
the upper portions of the volcano (above 1900 m on the southern
flank, currently unknown on the northern flank) is forbidden.
In fact, it IS dangerous to get close to the vent that is
still erupting, since bombs are sometimes thrown to a distance
of 1 km in all directions, and frequently shifting wind
directions may carry the dense tephra plume overhead.
There are currently no guided excursions offered at Etna,
and most tourist facilities have been severely damaged or
destroyed during both the 2001 and 2002 eruptions. Piano
Provenzana, on the northern flank, has been virtually deleted
from the face of Earth on the first day of the 2002 eruption.
With the onset of the winter season, visits to the summit
area of Etna and the sites of the 2002 eruption will be
close to impossible until next spring and reconstruction
of access roads.
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The
latest update is near the bottom of this page
Preliminary map of eruptive fissures
and lava flows produced by the 2002 eruption of Etna draped on a
digital elevation model (DEM) of the volcano. Location of fissures
and lava flows is based on maps posted on the web site of the Catania
section of the Istituto Nazionale di Geofisica e Vulcanologia (INGV-CT)
15
November 2002 update.
Eruptive
activity at the active cone at 2750 m elevation on the southern
flank of Mount Etna is continuing on its 20th day. Explosive activity
is alternating between ash-rich emissions and "dry" (ash-poor)
Strombolian bursts, and lava continues to flow from the fissure
at the southern base of the cone. An updated map of the new lava
flow is available at the INGV-CT
web site. A 15 November update on the same site gives an effusion
rate of 6.7 cubic meters per second. If that rate has been stable
since the onset of lava emission, about one million cubic meters
of lava have been emitted during the past two days so far.
Piano
Provenzana - a requiem
14
November 2002 update.
Lava
emission and explosive activity continue at the new cone on the
upper southern flank of Mount Etna. After one day of relatively
ash-free activity, the ash content in the plume from the active
cone has increased substantially during the afternoon of 13 November
and on 14 November, a westerly wind is blowing the plume to the
Giarre area.
Renewed lava emission started during the afternoon of 13 November
from a fissure on the southern slope of the new cone, coinciding
with the second largest new cone formed during the first days of
the eruption on the fracture on the upper southern flank. The crater
of this cone (extinct since early November) was filled with lava
before an overflow spilled over its western rim to form a flow directed
southwestward. By noon on 14 November, this flow had reached a length
of about 1.2 km (information from the web site of "La
Sicilia") and continued to advance on top of the lava flow
emplaced in late October 2002. A second overflow occurred to the
south, feeding a sluggish flow that advanced in the direction of
Monte Josemaria Escrivà, formed during the July-August 2001
eruption. This flow was reported stagnant by noon on 14 November.
The eruption is now continuing on its 19th day. While all activity
on the northeastern flank (where devastation has been greatest)
ended on 5 November (information via Volcano Listserver by Sonia
Calvari, INGV), the main vent on the eruptive fissure on the upper
southern flank has remained continuously active. During the days
after 5 November, the activity there seemed to diminish, but since
about 8 November it has remained more or less stable. Much of the
ash emissions from the cone may have been caused by magma-water
interaction at a shallow aquifer (although this awaits further analysis),
and a rise of the magma column above this aquifer may have led to
the change to purely magmatic (Strombolian) activity. A similar
evolution, though at a different time scale, has been observed during
the 2001 eruption at the cone on the former Piano del Lago (officially
named "Monte Josemaria Escrivà", although most
Etnean mountain guides continue to call it the "cono del laghetto").
According to a report in the Catania-based journal "La Sicilia"
on 12 November, the eruption produced 10-11 million cubic meters
of lava (mostly on the northeastern flank) and more 20 million cubic
meters of tephra through 11 November. The lava volume is thus only
about half the volume of lava emitted during the 2001 eruption,
but the volume of tephra is at least twice that emitted in 2001,
and the greatest emitted during any flank eruption of Etna since
1879.

Volcanologists
and Civil Protection staff watching explosive and effusive activity
at the new cone at 2750 m elevation on the southern flank of Etna
on the evening of 13 November 2002. New lava flow is visible as
incandescent ribbon below the explosion at the main vent of the
cone. Photo taken from the 14 November 2002 issue of "La Sicilia"
13
November 2002 update.
There
has been a change in the style of activity at the remaining active
vent on the upper southern flank of Mount Etna on 12 November. On
the afternoon of that day the ash plume which had risen into the
sky since the morning of 27 October, suddenly vanished, although
explosive activity continued with powerful Strombolian explosions.
As reported by numerous of the sources listed at the bottom of this
page, this change in the eruptive style coincided with a strong
increase in volcanic tremor, indicating an uprise of the magmatic
column within the conduit of the cone. On 13 November, Giuseppe
Scarpinati of Acireale estimated the frequency of explosions at
one every second. During the late afternoon of that day, the ash
content in the plume emitted from the new cone increased slightly.
At the same time, Charles
Rivière reported the appearance of a new lava flow at
2600 m elevation on the southern flank, which had been noted by
the head of the Forest Guards.
11
November 2002 update.
Explosive
eruptive activity is continuing without signs of diminishing at
the single still-active vent on the upper southern flank of Mount
Etna. This vent has built a sizeable pyroclastic cone with a height
of nearly 100 m above its southern base (its northern and western
flanks are less high due to the fact that the cone is growing on
a steep slope), whose crater is at least 100 m wide (see the spectacular
photos on the web sites of Charles
Rivière and Thorsten
Boeckel). The emissions occur as jets of bombs, lapilli, scoriae
and ash that are dark during daylight (except in a few rare cases
when incandescence is visible in the rising jets) but spectacularly
incandescent at night. There are sometimes significant variations
in the intensity and frequency of these jets; at sunset on 10 November
there were sometimes pauses of up to 2 minutes while at about 0530
h (local time) on 11 November the activity was continuous.
Shifting wind directions during the past few days have resulted
in complicated patterns of tephra distribution, although the most
commonly affected sectors vary from south to east. Light ash falls
occurred repeatedly in the Catania area, forcing the renewed closure
of the Fontanarossa International Airport.
5
November 2002 update.
On
the early morning of 27 October, a new flank eruption began at Etna
after only few hours of premonitory seismicity. This eruption was
more violent and more devastating than the previous flank eruption
in July-August 2001 and once more occurred from fissures on two
sides of the volcano: at about 2750 m on the southern flank, and
at elevations between 2500 and 2200 m on the northeastern flank,
in an area known as the Northeast Rift. After its extremely vigorous
start, the eruption showed a declining trend which continues as
of 5 November.
The tourist complex and skiing areas of Piano Provenzana were nearly
completely devastated by the lava flows that issued from the NE
Rift vents on the first day of the eruption. Heavy tephra falls
occurred mostly in areas to the south of the volcano and nearly
paralyzed public life in Catania and nearby towns. Strong seismicity
and ground deformation accompanied the eruption; a particularly
strong shock (magnitude 4.4) on 29 October destroyed and damaged
numerous buildings on the lower southeastern flank, in the area
of Santa Venerina.
The following is a summary of the events since the last update on
this site (2 June 2002) and a preliminary analysis of the significance
of this eruption in the framework of Etna's recent activity. Rather
than "Etna News", this report tempts to provide an overview
of the eruption in English language and in a comprehensive manner;
please note that some of the information is preliminary and thus
subject to possible change.
Prelude. Was there a prelude to the 2002 eruption
of Etna? Compared to the vigorous and spectacular summit eruptions
that had preceded the 2001 eruption, the 2002 eruption had very
few precursors, and in any case these did not permit to foresee
or predict the event. First, there was a relatively brief period
of mild summit activity, which started in mid-June with explosions
at the Bocca Nuova, and soon after the activity extended to the
Northeast Crater. Between early July and mid-September the Northeast
Crater was the site of Strombolian activity which led to a rapid
shallowing of its central pit, and at times bombs fell onto the
outer flanks of the Northeast Crater cone.
On 22 September, a magnitude 3.6 earthquake occurred on the northeastern
flank of Etna, in an area known as Piano Pernicana. This event was
accompanied by extensive ground fracturing, which was especially
notable on the "Mareneve" road, which connected the town
of Linguaglossa and Piano Provenzana. At the time the event was
not interpreted as being directly related to the eruptive activity
of the volcano, but a few days later, all activity at the summit
craters ceased, except for a few minor phreatomagmatic explosions
at the Northeast Crater. In hindsight, it might be speculated that
the earthquake signalled the opening of the Northeast Rift, and
magma drained from the central conduit system into the flank of
the volcano, causing the abrupt cessation of the summit activity.
For the following weeks the summit craters showed no activity except
quiet degassing. Mountain guides who visited the craters on Saturday
26 October noted nothing unusual, but late on that day magma began
to move within the volcano.
Precursory seismicity. An intense earthquake swarm
at shallow depth within the volcano began at approximately 2230
h (local time=GMT+2; note that the eruption beginning coincided
with the return from the Middle European Summer Time to the normal
Middle European Time), and this was the first clear indicator of
the impending eruption. A group of hikers staying at the Hotel "Le
Betulle" at Piano Provenzana, at about 1800 m elevation on
the northeastern flank of Etna, was awakened by the tremors and
had to abandon the building which was seriously damaged by the seismicity.
The seismic activity was caused by the rapid uprise of magma and
associated fracturing of the flanks of the volcano.
Eruption begins. At approximately 0200 h a few
persons watching the summit of Etna noted the sudden onset of high
lava fountaining from the Northeast Crater, which lasted only a
few minutes. Less than two hours later, lava fountaining began at
a new eruptive fissure at about 2700 m elevation on the southern
flank. This fissure lay about 1 km to the northwest of the largest
cone formed during the 2001 eruption (which a few weeks earlier
had been officially named "Monte Josemaria Escrivà").
The activity was accompanied by loud detonations and led to the
rapid growth of a large pyroclastic column, which was driven by
the wind to the south.
Shortly thereafter a second eruptive fissure became active in the
central portion of the Northeast Rift, in the area of a fissure
that was active in 1809. Eyewitnesses who stayed at Piano Provenzana,
only about 1.5 km downslope, stated that the opening of each new
vent was accompanied by strong seismicity, which destroyed or damaged
most of the structures at the tourist complex, and intense ground
fracturing. Lava began to issue from the new vents and to spill
down the slope above Piano Provenzana, destroying part of the ski
lifts in the area. The fissure gradually propagated downslopes,
generating more lava flows that came closer and closer to the buildings
at Piano Provenzana.
At dawn on 27 October, an enormous black cloud rose several kilometers
above the vents on the upper southern flank, while smaller ash columns
rose from the vents on the Northeast Rift. The plume was driven
southward over the densely populated areas around Catania, causing
heavy ash falls were to paralyze public life and traffic for several
days. The eruption was well visible even at great distance, such
as the Aeolian Islands, more than 100 km to the north. For many
hours the summit area of the volcano was completely veiled by the
ash clouds, and it was difficult to obtain a clear idea of what
was happening in the eruption area.
At noon on the same day, the first lava flow began to invade Piano
Provenzana, and a few hours later, the once verdant plain with its
touristic structures had been virtually obliterated by the lava.
Eruption progress, earthquakes and displacements.
By the afternoon of 27 October, the main lava flow which had buried
Piano Provenzana was rapidly advancing across the beautiful pine
forest of Linguaglossa (locally known as "Ragabo", a word
derived from the Arabian, which means "great forest").
Portions of the forest were set ablaze and helicopters and canadair
were busy in dousing the fires. At the fissure on the southern flank,
the activity was purely explosive (that is, no lava was emitted
from these vents), and the immediate surroundings of the fissure
were buried under a thick blanket of pyroclastics, transforming
much of the 2001 lava flows into a gray desert of scoriae and ash.
During the night of 27-28 October, the fissure on the Northeast
Rift propagated further downslope to an elevation of approximately
2200 m, and new lava flows began to advance along the lower portion
of the rift, passing on the eastern side of the large cone of Monte
Nero (formed during an eruption in 1646-1647). At the same time,
lava flowed for the first time from the lowermost vent on the southern
flank and formed a flow that advanced southwestward. This flow did
not threaten the tourist complex around the Rifugio Sapienza, which
had been seriously threatened by the 2001 eruption.
On 28 October it became clear that the eruption onset had been accompanied
by significant displacements along the Pernicana Fault on the northeastern
flank of Etna. The "Mareneve" road had been fractured
in numerous places, and displacements were observed in an area lying
between the lower portion of the Northeast Rift to the west and
the village of Vena to the east. Evidently a portion of the eastern
flank of the volcano had moved sideward, toward the sea. Continuing
movement was indicated by the continuing seismic activity, with
hundreds of minor earthquakes distributed in several areas on the
northeastern and eastern flanks. During the forenoon of 29 October,
these earthquakes became stronger and more frequent and culminated
in a magnitude 4.4 event, whose epicenter lay near the village of
Santa Venerina on the lower southeastern flank of Etna. Numerous
buildings in a portion of the village were damaged or destroyed,
and more than 1000 people left homeless; fortunately there were
no reports of serious injuries among the population. The earthquakes
dramatically increased the nervosism prevailing in the area since
the beginning of the eruption. One day later, a magnitude 5.4 earthquake
occurred several hundred kilometers to the north, in the region
of Molise (central-southern Italy), destroying buildings and causing
29 fatalities; this event was not related to the geodynamic activity
at Etna.
During the first days of the eruption, three of the four summit
craters were active as well. The Northeast Crater showed intermittent
Strombolian activity, indiating that magma was still at high levels
in the central conduit system, and ash was emitted periodically
from the Bocca Nuova and the Voragine. The Southeast Crater, which
had actively participated in the 2001 eruption (and the prelude
to that eruption) was entirely quiet.
Eruption wanes. On the third day of the eruption,
a distinct decrease of the intensity of the activity was evident.
The lava flows emitted from the Northeast Rift vents slowed; the
longest of these had reached a length of about 5.5 km and was still
far from the nearest town (Linguaglossa). A decrease in the effusion
rate was also noted at the fissure on the southern flank, but lava
fountaining accompanied by voluminous tephra generation continued,
and ash continued to fall onto Catania and neighboring areas, forcing
the continued closure of the Fontanarossa International Airport.
During the following days the eruptive activity continued at a consistently
decreasing trend. On the evening of 1 November the main lava flow
on the northeastern flank advanced at a speed of less than 1 m per
hour and 24 hours later it was nearly stagnant. Explosive activity
at the vents on the Northeast Rift decreased likewise. On 3 November,
only a very small portion of the lava flow near the eruptive vents
was active; on the southern flank all effusive activity had already
ceased by 1 November. The only site of continued vigorous eruptive
activity was the largest of the new vents on the southern flank,
where a large cone had grown. When observed on the evening of 3
November, this cone had more or less the same dimensions of its
one-year-old neighbor, Monte Josemaria Escrivà, being about
100 m high. Intermittent lava fountaining and abundant ash emission
continue as of 5 November, but it seems at this point that the eruption
is essentially over.
Volcanological features. The 2002 eruption has
been described in many reports as a highly unusual event for Etna,
and it seems that this is true. Firstly, this is one of the most
explosive eruptions of this volcano in recent times. Probably half
of the total volume of erupted products is pyroclastics, contrasting
with most recent eruptions of Etna which produced mainly (or nearly
exclusively) lava. Secondly, the 2002 eruption was actually two
eruptions in one, with two different types of magma being erupted
on the southern and northeastern flanks. The fissures on the Northeast
Rift produced the "common" Etna magma that has been produced
by all eruptions in the past few centuries, while the vents on the
southern flank produced a magma rich in amphibole, a water-bearing
mineral that has been relatively rare in recent products of Etna
until the 2001 eruption. In this sense the 2002 eruption is a repetition
of the events of July-August 2001, when the same two magma types
were erupted simultaneously from the different systems of eruptive
fissures. Thirdly, the invasion of Piano Provenzana and the "Ragabo"
forest by lava flows marks the end of a long, quiet period in that
area; no lava flows had occurred in these places in historic time.
The most recent major eruption on the Northeast Rift, in 1923, had
occurred a few hundred meters further west on the rift, so that
the lava flows traveled along-rift, in the direction of Linguaglossa,
while in 2002 most of the lava took a more easterly course.
The eruption produced a number of small scoria cones along the fissure
on the Northeast Rift and a cluster of huge cones at the vents on
the southern flank. These latter have once more completely changed
the topography of what was once known as the "Piano del Lago"
(the plain of the lake). Until 27 October 2002 this area bore the
scars of the 2001 eruption, most of it being covered with virtually
inaccessible lava flows and smaller and larger pyroclastic cones.
Now the formerly rugged surface has been transformed in a rolling
plain of ash, which will render future excursions on foot much more
easy. The abandoned station of the old cable car of Etna (partially
destroyed by an eruption in 1983) has been replaced by the lowermost
of the new cones, this will give a peculiar taste of thrill to those
who until shortly before the eruption used that building as a shelter
at night. The new souvenir shop and bar erected by the mountain
guides early in 2002 at 2760 m elevation has vanished under the
cover of pyroclastics, while the Torre del Filosofo mountain hut
at 2900 m elevation is still standing. Those who in the past arrived
at the Piano del Lago enjoyed a splendid panorama of the summit
cone complex; this will now be largely concealed by the new cones
at the fissure at 2700 m elevation.
The precise volumes of lava and pyroclastics emitted during the
2002 eruption is currently not known, but it seems that the eruption
produced somewhat less lava and much more pyroclastics than the
2001 eruption. In terms of magma volume, this is not a particularly
large eruption for Etna.
Outlook. The 2002 eruption came exactly 1 year,
3 months and 10 days after the beginning of the 2001 eruption. This
is a fairly short interval, even considering that between 1971 and
1993 flank eruptions occurred at a mean interval of 1.7 years. Yet,
in spite of the very brief period of precursory symptoms, this is
no surprise. After the 2001 eruption, several scientists knowing
Etna had assumed that the next eruption would occur within one to
two years, and in fact the eruption fell exactly into this time
window. The assumption is based on the historical behavior of the
volcano, which has undergone significant fluctuations during the
400 years of reasonably complete documentation since 1600. It seems
that flank eruptions tend to occur in series, and the 2001 eruption
was interpreted as the first in a new series, similar to the striking
series of 13 flank eruptions between 1971 and 1993. It thus seemed
probable that more such eruptions would occur at relatively brief
intervals over a period of 10-20 years. The 2002 eruption is the
second in the new series, and it is well possible that the third
one is not too distant in the future, especially in the light of
the relatively modest volumes of both the 2001 and 2002 eruptions.
Furthermore, the volcano was extensively fractured during both eruptions,
which in the future might allow magma much more easily to rise under
the flanks of the edifice. Last but least, Etna has grown progressively
more active during the past 50 years. This means, it is erupting
more frequently and more vigorously than during the 280 years before
1950, and its productivity, or output, is increasing. There is no
reason to believe that this trend will invert in the near future.
Flank eruptions must thus be expected to occur at intervals ranging
from 1-3 years, and some of them might be much more voluminous and
potentially hazardous than the latest two eruptions.
Download this report in PDF version (updated 7 November 2002)
- sorry for the typos, will be corrected soon -
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)
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
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 Giovanni
Pappalardo
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