Publication Date:
2017-04-04
Description:
We present results from a semi-automated field-emission scanning electron microscope investigation of
basaltic ash from a variety of eruptive processes that occurred at Mount Etna volcano in 2006 and at
Stromboli volcano in 2007. From a methodological perspective, the proposed techniques provide relatively
fast (about 4 h per sample) information on the size distribution, morphology, and surface chemistry
of several hundred ash particles. Particle morphology is characterized by compactness and elongation
parameters, and surface chemistry data are shown using ternary plots of the relative abundance of several
key elements. The obtained size distributions match well those obtained by an independent technique.
The surface chemistry data efficiently characterize the chemical composition, type and
abundance of crystals, and dominant alteration phases in the ash samples. From a volcanological perspective,
the analyzed samples cover a wide spectrum of relatively minor ash-forming eruptive activity,
including weak Hawaiian fountaining at Etna, and lava-sea water interaction, weak Strombolian explosions,
vent clearing activity, and a paroxysm during the 2007 eruptive crisis at Stromboli. This study outlines
subtle chemical and morphological differences in the ash deposited at different locations during the
Etna event, and variable alteration patterns in the surface chemistry of the Stromboli samples specific to
each eruptive activity. Overall, we show this method to be effective in quantifying the main features of
volcanic ash particles from the relatively weak – and yet frequent – explosive activity occurring at basaltic
volcanoes.
Description:
NL thanks generous support from the National Science Foundation
International Postdoctoral Research Program, grant OISE-
0754423. Funding was partially provided by FIRB-MIUR Project
‘‘Research and Development of New Technologies for Protection
and Defense of Territory from Natural Risks’’.
Description:
Published
Description:
113-127
Description:
1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
Description:
JCR Journal
Description:
reserved
Keywords:
ash
;
morphology
;
chemistry
;
Etna
;
Stromboli
;
04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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