Publication Date:
2017-04-04
Description:
We analyzed crater SO2 fluxes from Mt Etna, together with soil CO2 effluxes from the volcano's flanks, in the
period from 2001 to 2005. Between the 2001 and 2002–2003 eruptions, persistently low values of both
parameters suggest that no new gas-rich magma was accumulating at shallow depth (b5 km) within Etna's
central conduit, whereas very high SO2 sin-eruptive fluxes during the two eruptions indicated sudden
decompression of an un-degassed magma rising along newly-formed eccentric conduits. In November
2003, soil CO2 data indicate migration of gas-rich magma from deep (〉10 km) to shallow (b5 km) portions
of the feeding conduits, preceded by an increase in crater SO2 fluxes. A similar behavior was observed also
during and after the following 2004–2005 eruption. This degassing style matches a period of increased structural
instability of the volcanic edifice caused by acceleration of spreading that affected both its eastern and
southern flanks. Spreading could have triggered progressively deeper depressurization in the central conduit,
inducing release of the more soluble gas (SO2) first, and then of CO2, contrary to what was observed before
the 2001 eruption. This suggests that the edifice has depressurized, promoting ascent of fresh-magma and increasing
permeability favouring release of CO2 flux. By integrating geochemical and structural data, previous
degassing models developed at Mt. Etna have been updated to advance the understanding of eruptive events
that occurred in recent years.
Description:
This work was funded by grants from the Istituto Nazionale di
Geofisica e Vulcanologia (INGV) and from the Dipartimento per la
Protezione Civile (Italy).
Description:
Published
Description:
90-97
Description:
1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
Description:
1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
Description:
3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
Description:
3.6. Fisica del vulcanismo
Description:
4.5. Studi sul degassamento naturale e sui gas petroliferi
Description:
JCR Journal
Description:
reserved
Keywords:
Geochemical modeling
;
volcano monitoring
;
volcanic gases
;
Tectonics and magmatism
;
flank collapse
;
04. Solid Earth::04.01. Earth Interior::04.01.99. General or miscellaneous
;
04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous
;
04. Solid Earth::04.04. Geology::04.04.09. Structural geology
;
04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
;
04. Solid Earth::04.07. Tectonophysics::04.07.99. General or miscellaneous
;
04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics
;
04. Solid Earth::04.07. Tectonophysics::04.07.05. Stress
;
04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics
;
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::04.08.03. Magmas
;
04. Solid Earth::04.08. Volcanology::04.08.04. Thermodynamics
;
04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
;
04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
;
05. General::05.08. Risk::05.08.99. General or miscellaneous
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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