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Titel |
Multi-disciplinary investigation on a lava fountain preceding a flank eruption: the 10 May 2008 Etna case |
VerfasserIn |
Alessandro Bonaccorso, Andrea Cannata, Rosa Anna Corsaro, Giuseppe Di Grazia, Salvatore Gambino, Filippo Greco, Lucia Miraglia, Antonio Pistorio |
Konferenz |
EGU General Assembly 2011
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 13 (2011) |
Datensatznummer |
250053382
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Zusammenfassung |
A multidisciplinary approach integrating a wide dataset ranging from bulk rock
compositions of the erupted products to volcanic tremor, LP events, tilt and gravity
signals, is used to investigate the source depth and magma dynamics of the 10 May
2008 lava fountain at South-East crater (SEC) of Mt. Etna. The investigation was
undertaken in the framework of the previous 2007 explosive activity as well as
the subsequent effusive eruption beginning 13 May 2008 and lasting up to July
2009.
All the data concur in indicating that the 10 May lava fountain was generated by the
fragmentation of a foam layer trapped at the top of a shallow reservoir, about 1500-1700 m
below the summit of SEC. The shift from the episodic strombolian/lava fountains activity
occurring in 2007 at SEC to the more powerful 10 May lava fountain the following
year is explained by the intrusion of a new more primitive magma in the shallow
reservoir.
Furthermore, the presented data allows inferring that an attempted magma intrusion east
of the summit area occurred during the 10 May fire fountain. This event caused the fracturing
and weakening of the surrounding rocks and created a preferential pathway for the
penetration of the magma that, only three days later started to feed the 2008-2009 effusive
eruption. Finally, we speculate that the 13 May 2008 eruption could have been triggered by
the dynamic stress transfer from the M 7.9 earthquake that occurred on 12 May 2008 in
Sichuan (China). |
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