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This
is written in early January 2001, in a moment of calm on Etna, a chance
to reflect upon the eventful past few years. The spectacular natural fireworks
that we have admired and often failed to understand now seem like a dream
- yet we can be sure that we will not have to wait much to see that dream
once more become reality.
During
the year 2000, the summit eruptions of Etna have continued in a frantic
manner. This was especially the case during the first half of the year,
while towards the end ot 2000 the volcano has become quieter than ever
since the summit activity began in 1995. The activity which was concentrated
on the Southeast Crater (SEC), the youngest of the four summit craters
of Etna, was only the latest breathtaking act in an incredible show, but
in some respects superseded anything seen before at this volcano. The
following is an analytical review of Etna's activity in 2000 aimed at
placing this activity in a long-term context and highlights the main features
observed during the year. This is accompanied by photos not shown before
on this site. A few remarks about the personal experience of some of the
eruptive events are included.
Following
the spectacular October-November 1999 eruption of the Bocca Nuova and
the end of the nine months-long effusive activity at the southeastern
base of the SEC cone, the volcano showed relatively modest levels of activity
through late January 2000. In this period the only site of eruptive activity
was the Bocca Nuova, which produced alternating weak Strombolian activity
and ash emissions. The SEC, which had been very active between 1996 and
1999 was perfectly silent and showed only minor fumarolic activity.
ERUPTIVE
ACTIVITY RESUMES, LATE JANUARY 2000
Early
on 26 January 2000 the SEC reawoke unexpectedly and violently, with Strombolian
bursts which gradually intensified and culminated in a paroxysmal eruptive
episode later that morning. Like during its previous paroxysm, on 4 February
1999, the SEC cone fractured on its flank, but rather than towards SE,
the new fracture extended from the summit of the cone towards S. The paroxysmal
phase of this new eruptive episode was over after a few hours, but lava
continued to pour from the lower end of the new fissure through the late
envening, so that it seemed that a similar situation to that of 4 February
1999 had been created. Howeever, the next day all effusive activity had
ended, and it became clear that this time the paroxysm would not be followed
by a long-lived outflow of lava as one year earlier.
But
three days after the first paroxysm, on the morning of 29 January, the
SEC erupted again. This time the paroxysm lasted only about 15 minutes,
but it produced a spectacular mushroom-shaped plume in the clear sky of
this nearly windless morning. At the height of the paroxysm the fracture
on the S flank of the cone reopened, and for a brief period foundains
played from numerous.
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Southeast
Crater
Eruptive
episodes of January-April 2000
No. 01: 26 January (0100-1300); lava continues to flow until
the late evening
No. 02: 29 January (0845-0900); lava flows until nightfall
No. 03: 01 February (0900-1000)
No. 04: 02 February (0800-0830)
No. 05: 03 February (0800-0900)
No. 06: 04 February (0950-1020)
No. 07: 05 February (0010-0030)
No. 08: 05 February (1200-1230)
No. 09: 06 February (0430-0500)
No. 10: 06 February (2300-2330)
No. 11: 07 February (1650-1710)
No. 12: 08 February (1130-1145)
No. 13: 08 February (2000-2015)
No. 14: 09 February (0700-0800)
No. 15: 10 February (0020-0100)
No. 16: 10 February (1330-1345)
No. 17: 10 February (2130-2300)
No. 18: 11 February (0530-0550); four spectacular fire-fountains
No. 19: 11 February (2200-2220)
No. 20: 12 February (0350-0430)
No. 21: 12 February (0945-1030)
No. 22: 13 February (0030-0050); occurred during very bad
weather
No. 23: 13 February (1240-1300)
No. 24: 14 February (0300-0330)
No. 25: 14 February (1600-1630)
No. 26: 15 February (1800-1820); the most violent episode
of the sequence
No. 27: 16 February (0640-0700)
No. 28: 16 February (1605-1615)
No. 29: 17 February (0500-0530)
No. 30: 17 February (1310-1330)
No. 31: 17 February (2130-2200)
No. 32: 18 February (0730-0800)
No. 33: 18 February (1640-1700)
No. 34: 19 February (0900-0945)
No. 35: 20 February (1700-1820)
No. 36: 23 February (0245-0435)
No. 37: 27 February (0645-0950)
No. 38: 28 February (1630-1730)
No. 39: 04 March (0400-0450)
No. 40: 08 March (0745-1030)
No. 41: 12 March (1300-1415); activity mainly at the "Sudestino"
No. 42: 14 March (0710-0740); lava surrounds Torre del Filosofo
No. 43: 19 March (0100-0330); activity concentrated at the
"Sudestino"
No. 44: 22 March (1945-2100); lava from fissures on N and
S flanks
No. 45: 24 March (1940-2035)
No. 46: 29 March (2000-2200)
No. 47: 01 April (forenoon); some activity also at the "Sudestino"
No. 48: 03 April (around 1600); SEC cone fractures only
on N side
No. 49: 06 April (1200-1300); SEC cone fractures only on
N side
No. 50: 16 April
No. 51: 26 April
No. 52: 05 May
No. 53: 15 May
No. 54: 15 May
No. 55: 18 May
No. 56: 20 May
No. 57: 23 May
No. 58: 27 May
No. 59: 01 June
No. 60: 01 June
No. 61: 05 June
No. 62: 08 June
No. 63: 14 June
No. 64: 24 June
No. 65: 28 August
No. 66: 29 August
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Photos
of the activity in 2000
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Two
views of Etna emitting a dense gas plume, shortly after
the paroxysmal eruptive episode #8 at about 1320 h on 5
February, seen from the Belpasso area on the lower SSW flank
of Etna. Photos by Giovanni Sturiale
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Eruptive
episode #14 on the morning of 9 February, seen from the
home of Giovanni Sturiale in Sant'Agata li Battiati (S of
Etna). Note weather front approaching from SW. Photos by
Giovanni Sturiale
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Large
scoria clast, about 25 cm long, and weighing 0.9 kg, ejected
during the eruptive episode (#24) of the afternoon of 14
February 2000, and fallen near the Torre del Filosofo mountain
hut (about 1 km south of the Southeast Crater). Even larger
scoria clasts were found in the same area, testifying to
the violence of the eruptive episode and the importance
of the wind direction during the event: Torre del Filosofo
was precisely downwind from the erupting crater. Photo by
Giuseppe Scarpinati
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Spectacular
eruption column rising from the Southeast Crater during
a violent eruptive episode (#26) on the morning of 16 February
2000. The plume is rising about 5 km above the summit of
Etna, and is seen here from the home of Giuseppe Scarpinati
(who took these photos) in Acireale. Much detail of the
upper part of the volcano is visible, thanks to the illumination
from the southeast (corresponding to the location of Acireale
relative to Etna)
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Another
paroxysm at the Southeast Crater (#32) is seen here during
the afternoon of 18 February. Strong northerly wind is blowing
the plume to the south, causing ash falls in the Catania
area. However, this episode appears less violent than that
on 16 February. This view is again from Scarpinati's home
in Acireale
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Photos
of a visit to the Southeast Crater area on 11 March, 3 days
after eruptive episode #39. Left photo is one of the last
images of the Torre del Filosofo building (visible near
left margin of photo) before it was encircled by lava flows
on 14 March. These flows originated at the "Sudestino",
a new major eruptive vent at the southern base of the SE
Crater cone, both of which are shown in the center photo.
The right photo, a zoom on the "Sudestino", shows
more detail of this peculiar vent. Photos by Boris Behncke
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Southeast
Crater and "Sudestino" are seen in the photos
at left and center on 16 March, two days after eruptive
episode #41, which produced large volumes of lava and seriously
threatened the Torre del Filosofo mountain hut. Left photo
is one of the few clear views of the SE Crater cone that
could be obtained that rainy and stormy day; the dark, shield-shaped
hill at the base of the sulfur-coated fracture on the near
side of the SE Crater cone is the "Sudestino".
This feature is more apparent in the center photo, when
a cloud cast a shadow on the "Sudestino", while
much of the SE Crater cone is in clouds. Right photo shows
a peculiar debris flow deposit on the slope below the Torre
del Filosofo; this was deposited after lava rapidly melted
snow near Torre del Filosofo on 14 March. Photos by Boris
Behncke
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The
dramatic effects of the 14 March eruptive episode (#41)
are visible at Torre del Filosofo in these photos taken
two days after the event: left photo shows a small gorge
eroded into the ground near the SE side of the Torre del
Filosofo building. Erosion was caused by a small flash flood,
generated by rapid snow melt as the lava burned a small
wooden hut standing next to the Torre del Filosofo building,
which was itself encircled by the lava (center and right
photos). The lava rose almost to the height of the lower
part of the building's roof, piling against the building
to a height of up to 4 m. Photos by Boris Behncke
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Left:
View from the summit of Monte Frumento Supino (a flank cone
high on the SSW flank of Etna) towards the summit cone complex.
Lava flows erupted in mid- to late-March from the SE Crater
(which is visible at right) have extended across the plain
at the southern base of the summit cone complex (whose surface
lies higher than the summit of Monte Frumento Supino) and
then spilled down the steep slope to the south of the plain
(foreground). Photo was taken by Boris Behncke on 25 March
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This
chaotic place is what remains of the northwestern rim of
the Bocca Nuova. The crater was changed beyond recognition
during its October-November 1999 eruptions, and this and
the following three photos are the first taken in the area
by Behncke since that activity. The sharp peak at left corresponds
roughly to a small crest known as "Monumento"
until October 1999. The depression lying in the foreground
is a notch formed during the October-November 1999 activity
when lava broke through the crater rim and flowed onto the
W flank of Etna. Photo taken by Boris Behncke on 25 March
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Left:
View towards W from pinnacle formed in late October 1999
on the W rim of the Bocca Nuova
Right: View from same point towards SW rim of Bocca Nuova.
During the 1999 eruptions, lava overflowed from the crater
between yellow area in the foreground and steaming area
in the background. Photos taken by Boris Behncke on 25 March
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Left:
The structurally complex area which once was the NW rim
of the Bocca Nuova
Right: Fissured ground and sulfur deposits at the N rim
of the Bocca Nuova; rim of the Voragine is in the background.
Photos taken by Boris Behncke on 25 March
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Left:
SE Crater cone seen from SE part of former Central Crater.
It is now higher than the point from which the photo was
taken
Right: View from SE part of main summit cone onto recent
lava flows from SE Crater, outlined in red. Other features
are annotated. TDF=Torre del Filosofo; VDB=Valle del Bove.
Photos taken by Boris Behncke on 25 March
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