Publication Date:
2017-04-04
Description:
The October 17 to November 5, 1999, eruption of Mount Etna’s Bocca Nuova crater emplaced a V15U106 m3
flow field. The eruption was characterized by 11 paroxysmal events during which intense Strombolian and lava
fountain activity fed vigorous channelized PaPa flows at eruption rates of up to 120 m3 s31. Each paroxysm lasted
between 75 and 450 min, and was separated by periods of less intense Strombolian activity and less vigorous (610 m3
s31) effusion. Ground-based, satellite- and model-derived volumetric data show that the eruption was characterized by
two periods during which eruption rates and cumulative volume showed exponential decay. This is consistent with a
scenario whereby the system was depressurized during the first eruptive period (October 17^23), repressurized during
an October 24 pause, and then depressurized again during the second period (October 25^28). The imbalance between
the erupted and supplied volumes mean that the two periods involved the collection of 1.5^5.7U106 m3 and 1.2^
3.6U106 m3, respectively, or an increase in the time-averaged supply to 11.6^13.6 m3 s31 and 12.5^14.9 m3 s31. Two
models are consistent with the observed episodic fountaining, derived volumetric trends and calculated volume
imbalance: a magma collection model and a pulsed supply model. In the former case, depressurization of a shallow
reservoir cause the observed volumetric trends and foam collapse at the reservoir roof powers fountaining. In the
pulsing case, variations in magma flux account for pressurization^depressurization and supply the excess volume.
Increases in rise rate and volatile flux, coupled with rapid exsolution during ascent, trigger fountaining. Limiting
equations that define critical foam layer volumes and magma rise rates necessary for Hawaiian-style fountaining favor
the latter model.
Description:
Published
Description:
79-95
Description:
1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
Description:
3.5. Geologia e storia dei sistemi vulcanici
Description:
3.6. Fisica del vulcanismo
Description:
4.3. TTC - Scenari di pericolosità vulcanica
Description:
JCR Journal
Description:
reserved
Keywords:
Etna
;
lava fountaining
;
eruption rates
;
lava channel
;
foam layers
;
rise rates
;
04. Solid Earth::04.01. Earth Interior::04.01.99. General or miscellaneous
;
04. Solid Earth::04.01. Earth Interior::04.01.05. Rheology
;
04. Solid Earth::04.02. Exploration geophysics::04.02.99. General or miscellaneous
;
04. Solid Earth::04.02. Exploration geophysics::04.02.05. Downhole, radioactivity, remote sensing, and other methods
;
04. Solid Earth::04.02. Exploration geophysics::04.02.07. Instruments and techniques
;
04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous
;
04. Solid Earth::04.04. Geology::04.04.11. Instruments and techniques
;
04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
;
04. Solid Earth::04.08. Volcanology::04.08.01. Gases
;
04. Solid Earth::04.08. Volcanology::04.08.02. Experimental volcanism
;
04. Solid Earth::04.08. Volcanology::04.08.03. Magmas
;
04. Solid Earth::04.08. Volcanology::04.08.04. Thermodynamics
;
04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
;
04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
;
04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
;
04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
;
05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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