Publication Date:
2017-04-04
Description:
During 2007–2008, three CO2 flux surveys were
performed on El Chichón volcanic lake, Chiapas, Mexico,
with an additional survey in April 2008 covering the entire
crater floor (including the lake). The mean CO2 flux
calculated by sequential Gaussian simulation from the lake
was 1,190 (March 2007), 730 (December 2007) and
1,134 g m−2 day−1 (April 2008) with total emission rates
of 164±9.5 (March 2007), 59±2.5 (December 2007) and
109±6.6 t day−1 (April 2008). The mean CO2 flux
estimated from the entire crater floor area was
1,102 g m−2 day−1 for April 2008 with a total emission
rate of 144±5.9 t day−1. Significant change in CO2 flux was
not detected during the period of survey, and the mapping
of the CO2 flux highlighted lineaments reflecting the main
local and regional tectonic patterns. The 3He/4He ratio (as
high as 8.1 RA) for gases in the El Chichón crater is
generally higher than those observed at the neighbouring
Transmexican Volcanic Belt and the Central American
Volcanic Arc. The CO2/3He ratios for the high 3He/4He
gases tend to have the MORB-like values (1.41×109), and
the CO2/3He ratios for the lower 3He/4He gases fall within
the range for the arc-type gases. The high 3He/4He ratios,
the MORB-like CO2/3He ratios for the high 3He/4He gases
and high proportion of MORB-CO2 (M=25 ±15%) at El
Chichón indicate a greater depth for the generation of
magma when compared to typical arc volcanoes.
Description:
Published
Description:
423-441
Description:
2.4. TTC - Laboratori di geochimica dei fluidi
Description:
JCR Journal
Description:
reserved
Keywords:
El Chichon
;
CO2 soil flux
;
Crater Lake
;
Gas geochemistry
;
He-C isotopes
;
Fumarolic and bubbling gases
;
Tectonics
;
04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
;
04. Solid Earth::04.05. Geomagnetism::04.05.08. Instruments and techniques
;
04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring
;
04. Solid Earth::04.08. Volcanology::04.08.01. Gases
;
04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
;
05. General::05.02. Data dissemination::05.02.01. Geochemical data
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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