|
Short activity updates
24 May 2005:
Updates on Stromboli volcano are now continued on
VolcanoDiscovery's website at:
http://www.volcanodiscovery.com/volcano-tours/volcanoes/europe/itay/stromboli/updates.html
9 March 2004:
Apparently, the activity at Stromboli volcano has again increased
significantly during the past weeks, with near continuous strong eruptions
from all craters, which indicates an unusually high magma level inside the
conduit, that in turn might well soon lead to another lava flow or even
flank eruption. To get an impression, the colleagues from
Stromboli On Line have compiled a
beautiful collection of photos from the
live cam maintained by the INGV
Catania, who also released the following official report:
<<
Explosive activity at the summit craters of Stromboli volcano resumed on
early June 2003, before the end of the effusive eruption that finished
between 21 and 22 July 2003. Eruptive activity at this volcano is
continuously monitored by INGV-CT using two web cameras located at Il
Pizzo Sopra la Fossa (920 m a.s.l.) and at 400 m elevation along the east
margin of the Sciara del Fuoco, the depression on the north flank of the
volcano that contains the summit craters. Additionally, a web thermal
camera is also located at the 400 m elevation site, and a web infrared
camera at Il Pizzo Sopra la Fossa. The thermal and video cameras at 400 m
elevation give important insights when visibility of the summit is poor or
craters are surrounded by clouds. The infrared video camera at Il Pizzo
allows a continuous view of the activity at the summit craters, and a
quantification of the energy released by the explosions at the three
summit craters through an automated system
called VAMOS (Cristaldi et al., 2004).
Explosive activity at the three summit craters increased after 10 February
2004, leading to a significant growth of the cinder cones inside the three
summit craters. Several powerful explosions, especially from crater 1 (the
NE-crater) and crater 3 (the SW-crater) carried scoria 200 m above the
craters. These powerful explosions led to fallout of fresh bombs and
lapilli on Il Pizzo Sopra la Fossa in early March. Samples of lapilli and
scoria collected on Stromboli by local guides have been analysed with the
scanning electron microprobe and microanalysis instruments of INGV-CT (Corsaro
et al., 2004). Measurements of glass compositions evidence that products
erupted until 25 February 2004 belong to the "black scoriaceous volcanics"
normally erupted during Strombolian activity. No "golden basaltic pumices"
were present in available samples. Emission of golden pumice at this
volcano is generally associated with paroxysmal explosive events (Bertagnini
et al., 1999) such as that of 5th April 2003. Analysis of components
carried out on several ash samples allowed us to recognize sideromelane
and tachylite as the main components, making up ~80% of the erupted ash (Andronico
et al., 2004). The activity of this volcano at the time of writing (8
March 2004) can be described as Strombolian activity, with variations in
the number and frequency of explosions within normally observed limits,
and intensity of explosions at the higher limit of commonly observed
activity.
References:
- Andronico D., Caruso S., Cristaldi, A., and Del Carlo P. (2004) -
Caratterizzazione delle ceneri emesse dallo Stromboli nel Gennaio-Febbraio
2004. INGV-CT Internal Report, Prot. int. n°
UFVG2004/34, pp 2.
- Bertagnini, A., Coltelli, M., Landi, P., Pompilio, M., Rosi, M. (1999) -
Violent explosions yield new insights into dynamics of Stromboli volcano.
Eos, American Geophysical Union Transactions, 80, 52: 633-636.
- Corsaro R.A., Miraglia L., Zanon V. (2004) - Caratterizzazione dei vetri
presenti nei prodotti emessi dallo Stromboli durante il mese di febbraio
2004. INGV-CT Internal Report, Prot. int. n° UFVG2004/33, pp 4.
- Cristaldi A., Coltelli M., Mangiagli S. (2004) - Rapporto settimanale
sull'attivitą eruttiva dello Stromboli: 22 - 29 Febbraio 2004. INGV-CT
Internal Report, Prot. int. n° UFVG2004/31, pp 2.
>>
4 February 2004:
3 eruption
videos from 7 December 2003 have been added to the photo section. See
also the report below.
28 January: photos and a report from Dec.
2003
Thanks to the cooperation with the partner-site "From
Etna to Stromboli" by Thorsten Boeckel, an interesting report of a
small group of visitors to Stromboli in December 2003 has become
available. It illustrates the present situation and policy concerning the
current ufficial restrictions to the summit area. An abbreviated and
slightly modified version is presented here:
"...it is still difficult
and forbidden by law to ascend the summit of Stromboli. Further restless
phases of the volcano were registered to the turn of the year 03/04.
Nevertheless, R. Schulz and friends succeeded at the 7 of December in
staying at a position where it was possible to get an exiting view into
the new crater and making some interesting photos from the eruptive
ejections and the changing summit region.
When we reached the altitude of 400 m (helicopter landing place and live
camera), we were loudly called. A policeman (in civil clothes, but with an
ID document), a mountain guide and a further
person came up. They explained us that we
were already too far (above
290m which is permitted). After long discussions they said that we could
remain on the altitude of 400m, if we would ascend neither still further
high nor would stay overnight. They descended then with the
beginning of the dawn.
...At night it rained and it was strongly cloudy
on the next morning...In the afternoon we ascended
again and the wind turned to north. This was our luck, because the whole
clouds were blown away to the south and the summit was free. This time
crater 1 was full active, partly in a minute interval."
A. Fisher and his friends managed to take spectacular photos that
document the strong activity of Stromboli' s NE crater, which lasted this
way until the beginning of January 2004, before returning to the present
lower levels:
   
Stromboli's NE crater in activity during late evening of 7 Dec. 2003.
(photo copyrights A. Fisher /
photos@decadevolcano.net)
|
|
18 January 2004: Update -
decreasing levels of activity
As judged from direct observation and other reports, the
summit activity has decreased significantly and/ or is characterized by
strong fluctuations on the temporal order of several days or even weeks. During a
visit on 11 January, only weak explosive activity was present from 3 of 5
active vents. NE crater erupted approximately every 30-40 minutes throwing
bombs no higher than about 100m with few material landing outside the
crater. The central crater was observed as a glowing pit that emitted weak
jets of gas and occasionally some spatter. NW crater continued to erupt
mainly brown ash mixed with few incandescent material.
The activity can sometimes be followed from the new
livecam at Pizzo, re-installed
by INGV. Some nice impressions from archived photos have been carefully
collected by the team of the partner site
Stromboli OnLine and can be seen
here.
9 January 2004: Update
- continuing intense strombolian activity
According to various (unconfirmed) reports from local
guides and climbers, strombolian activity at the summit craters of
Stromboli has been continuing at a high level throughout the past months
and is essentially unchanged since Tom and a group of decadevolcano.net
last visited the summit area in September 2003 (photos).
Apparently, 5 active vents are present, 3 of which are
forming a cluster belonging to the re-growing NE crater (towards Stromboli
village) and are erupting frequently, at times as near-continuous
spattering. Occasionally, very strong explosions occur,
throwing bombs to 3-400 m above the crater. At the site of the
former central crater, a glowing vent is present that erupts with loud
hissing noises about every 10 (?) minutes, but ejects
mostly gas and relatively little incandescent material in a narrow jet.
The NW crater (towards Ginostra) continues to eject mainly brown ash with
little fresh glowing scoria, forming distinct small mushroom plumes.
Restrictions to the summit area:
Note that the ufficial restrictions for all non-authorized persons to
climb over 400 m are still fully in place, although it appears that at the
present time it is not always being inforced. According to rumors, the
ufficial state of emergency (or "the volcanic crisis" etc., being the
legal justification for the massive presence of Civil Protection forces)
and the resulting strict regulations to access the summit area are
scheduled to be (or have been) prolongued for a second year. This is a
subject of a highly controversial debate on Stromboli itself (that is not
discussed further here). However, with the beginning of the tourist
season, another larger employment of Civil Protection forces in
cooperation with volcanologist is likely.
---
Archived updates: [2003]
|
