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| Titel |
Relationships between lava and tephra volumes erupted during the 26 October 2013 lava fountaining episode from the New Southeast Crater of Etna |
| VerfasserIn |
Daniele Andronico, Boris Behncke, Antonio Cristaldi, Emanuela De Beni, Maria Deborah Lo Castro, Manuela Lopez, Simona Scollo |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250093402
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| Publikation (Nr.) |
 EGU/EGU2014-8087.pdf |
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| Zusammenfassung |
| Determining the volume of the various products of a volcanic eruption can be notoriously
difficult, especially if the products encompass lava, distal tephra, and proximal pyroclastics
mostly deposited on a growing volcanic cone. We evaluated, for the first time at Etna, the
total masses and volumes of both lava flows and pyroclastic material emitted during the 26
October 2013 episode of lava fountaining at Etna’s New Southeast Crater (NSEC),
correlating them with mass eruption rate and total grain-size of the fallout deposit. The
episode was heralded by Strombolian activity starting on early 25 October and
gradually intensifying throughout the day, blending into a continuous lava fountain
early on 26 October. An eruption column started to rise to ~4 km above Etna’s
summit before being bent toward WSW by the wind. Lava fountaining up to 500
m high continued until ~10:00 GMT, and then started to diminish significantly;
by 13:00 GMT, the episode was over. ‘A‘¯a lava flows were emitted throughout
the phase of lava fountaining, forming a three-lobed lava field toward south and a
minor lava flow toward east. After the episode, we carried out field surveys to map
both the fallout deposits and the lava flows. Distal tephra was deposited to at least
110 km distance from the vent and possibly beyond the south coast of Sicily. The
dispersal area of the tephra deposit was quite narrow on the ground, the load per
unit area declining very rapidly away from the main dispersal axis. In the very
proximal area (~1.6 km from the NSEC), the fallout deposit formed a 3-cm thick bed
of scoriaceous lapilli (peaked at -2 phi) amounting to 22.25 kg/m2. The tephra
load dropped up to 0.4 kg/m2 in the town of Adrano (16 km), where we found a
continuous, thin layer of medium-sized ash. Finally, the fallout consisted of fine
ash (~99 % of clasts |
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