Publication Date:
2017-04-04
Description:
We measured volcanic gas emissions from the northeast crater (NEC) and central crater (CC) of Mount Etna
on 21st July 2008, and 3rd and 31st August 2009, using a novel, lightweight open-path Fourier transform
infrared spectrometry (OP-FTIR) in active mode with a portable infrared lamp. Contemporaneously we
measured the SO2 flux of the total gas emission released by the combined summit craters 14 km downwind
and the SO2 flux emitted by the NEC measured at the summit. Combining these data we determined the flux of
the major volcanic components H2O, CO2, SO2, HCl and HF emitted individually from CC and NEC craters. The
results reveal similar SO2/HCl ratios but distinct CO2/SO2 ratios (1.3 and 10.9 for NEC and CC, respectively) and
an order of magnitude greater CO2 flux from the CC compared with the NEC. A simple model in which the NEC
branches from a central feeding conduit at a depth of ~2 km can reproduce these observations. We highlight
that in such a system short-term variations in CO2/SO2 ratios at each crater can occur due to minor variations
in the magma/gas flux entering each conduit at the branch, without an overall change in magma supply. CO2/
SO2 variations measured at individual craters may therefore be unrepresentative of the volcanic system and
require cautious interpretation. Monitoring of the total CO2 and SO2 fluxes emitted from each crater is, on the contrary, an optimal monitoring strategy and can be achieved using a combination of CO2/SO2 instruments and SO2 imaging cameras
Description:
INGV-DPC “Sicilia” Project (Gas plumeTask).
Description:
Published
Description:
368-376
Description:
1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
Description:
JCR Journal
Description:
reserved
Keywords:
magma degassing, OP-FTIR, Mt. Etna
;
04. Solid Earth::04.08. Volcanology::04.08.01. Gases
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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