Multi-component gas analyzer system

File:Multi-Component Gas Analyzer (Multi-GAS) permanent station.jpg

Multi-component gas analyzer systems are used for measuring the major components of volcanic gases. CO₂, SO₂, H₂S, and pressure-temperature-humidity sensors are typically included in a package.{{Cite journal|last1=Gudjónsdóttir|first1=Sylvía Rakel|last2=Ilyinskaya|first2=Evgenia|last3=Hreinsdóttir|first3=Sigrún|last4=Bergsson|first4=Baldur|last5=Pfeffer|first5=Melissa Anne|last6=Michalczewska|first6=Karolina|last7=Aiuppa|first7=Alessandro|last8=Óladóttir|first8=Audur Agla|date=2020|title=Gas emissions and crustal deformation from the Krýsuvík high temperature geothermal system, Iceland|url=http://www.sciencedirect.com/science/article/pii/S0377027317303359|journal=Journal of Volcanology and Geothermal Research|language=en|volume=391|pages=106350|doi=10.1016/j.jvolgeores.2018.04.007|bibcode=2020JVGR..39106350G|s2cid=135167976|issn=0377-0273|hdl=10447/347068|hdl-access=free}} Other electrochemical sensors have been successfully incorporated as well, including for H₂{{Cite journal|last1=Aiuppa|first1=A.|last2=Shinohara|first2=H.|last3=Tamburello|first3=G.|last4=Giudice|first4=G.|last5=Liuzzo|first5=M.|last6=Moretti|first6=R.|date=2011|title=Hydrogen in the gas plume of an open-vent volcano, Mount Etna, Italy|url=https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2011JB008461|journal=Journal of Geophysical Research: Solid Earth|language=en|volume=116|issue=B10|pages=B10204|doi=10.1029/2011JB008461|bibcode=2011JGRB..11610204A|issn=2156-2202|hdl=10447/104567|hdl-access=free}} and HCl.{{Cite journal|last1=Roberts|first1=T. J.|last2=Lurton|first2=T.|last3=Giudice|first3=G.|last4=Liuzzo|first4=M.|last5=Aiuppa|first5=A.|last6=Coltelli|first6=M.|last7=Vignelles|first7=D.|last8=Salerno|first8=G.|last9=Couté|first9=B.|last10=Chartier|first10=M.|last11=Baron|first11=R.|date=2017|title=Validation of a novel Multi-Gas sensor for volcanic HCl alongside H2S and SO2 at Mt. Etna|url= |journal=Bulletin of Volcanology|language=en|volume=79|issue=5|pages=36|doi=10.1007/s00445-017-1114-z|issn=1432-0819|pmc=6979509|pmid=32025075|bibcode=2017BVol...79...36R}} The instruments are packaged in compact, portable, weather-resistant containers allowing for in situ measurements of various types of outgassing terrains. Gas is pumped into the system at a constant flow rate through a silicone tube placed near the location of interest. A data-logger is used to automatically record and convert the voltage values from the sensors into gas composition values. While the field use of a multi-GAS is simple, postprocessing of the data can be complex. This is due to factors like instrument drift, and atmospheric or environmental conditions. The system can be used for short term or long term studies. Short term usage can include powering the multi-GAS by a lithium battery and moving it around to desired locations{{Cite journal|last1=Woitischek|first1=Julia|last2=Woods|first2=Andrew W.|last3=Edmonds|first3=Marie|last4=Oppenheimer|first4=Clive|last5=Aiuppa|first5=Alessandro|last6=Pering|first6=Tom D.|last7=Ilanko|first7=Tehnuka|last8=D'Aleo|first8=Roberto|last9=Garaebiti|first9=Esline|date=2020|title=Strombolian eruptions and dynamics of magma degassing at Yasur Volcano (Vanuatu)|url=http://www.sciencedirect.com/science/article/pii/S0377027319306225|journal=Journal of Volcanology and Geothermal Research|language=en|volume=398|pages=106869|doi=10.1016/j.jvolgeores.2020.106869|bibcode=2020JVGR..39806869W|s2cid=219009925|issn=0377-0273|hdl=10447/498832|hdl-access=free}}{{Cite journal|last1=Lages|first1=J.|last2=Chacón|first2=Z.|last3=Burbano|first3=V.|last4=Meza|first4=L.|last5=Arellano|first5=S.|last6=Liuzzo|first6=M.|last7=Giudice|first7=G.|last8=Aiuppa|first8=A.|last9=Bitetto|first9=M.|last10=López|first10=C.|date=2019|title=Volcanic Gas Emissions Along the Colombian Arc Segment of the Northern Volcanic Zone (CAS-NVZ): Implications for volcano monitoring and volatile budget of the Andean Volcanic Belt|url=https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GC008573|journal=Geochemistry, Geophysics, Geosystems|language=en|volume=20|issue=11|pages=5057–5081|doi=10.1029/2019GC008573|bibcode=2019GGG....20.5057L|hdl=10447/386634|s2cid=210304262|issn=1525-2027|hdl-access=free}} or setting up a multi-GAS in a fixed location for a short period of time.{{Cite journal|last1=de Moor|first1=J.M.|last2=Aiuppa|first2=A.|last3=Pacheco|first3=J.|last4=Avard|first4=G.|last5=Kern|first5=C.|last6=Liuzzo|first6=M.|last7=Martinez|first7=M.|last8=Giudice|first8=G.|last9=Fischer|first9=T.P.|date=2016|title=Short-period volcanic gas precursors to phreatic eruptions: Insights from Poás Volcano, Costa Rica|url=https://www.sciencedirect.com/science/article/pii/S0012821X16300851|journal=Earth and Planetary Science Letters|language=en|volume=442|pages=218–227|doi=10.1016/j.epsl.2016.02.056|bibcode=2016E&PSL.442..218D|issn=0012-821X|hdl=10447/227127|hdl-access=free}} Long term studies involve setting up a permanent installment for an extended time.{{Cite journal|last1=Lewicki|first1=J. L.|last2=Kelly|first2=P. J.|last3=Bergfeld|first3=D.|last4=Vaughan|first4=R. G.|last5=Lowenstern|first5=J. B.|date=2017|title=Monitoring gas and heat emissions at Norris Geyser Basin, Yellowstone National Park, USA based on a combined eddy covariance and Multi-GAS approach|url=http://www.sciencedirect.com/science/article/pii/S0377027317304407|journal=Journal of Volcanology and Geothermal Research|language=en|volume=347|pages=312–326|doi=10.1016/j.jvolgeores.2017.10.001|bibcode=2017JVGR..347..312L|issn=0377-0273|url-access=subscription}} These stations can be set-up with terrestrial (e.g. 3G) or satellite{{cite web |last1=Brynnams |url=https://commons.wikimedia.org/wiki/File:Multi-Component_Gas_Analyzer_(Multi-GAS)_permanent_station.jpg |website=Wikimedia Commons |access-date=18 October 2023 |title=Multi-Component Gas Analyzer (Multi-GAS) permanent station|date=4 October 2020 }}{{cite journal |last1=Madonia |first1=Paolo |title=Variations of low temperature fumaroles as a tool for detecting changes in volcanic activity state: a brief overview |journal=Advances in Geosciences |date=24 November 2020 |volume=52 |pages=99–100 |doi=10.5194/adgeo-52-97-2020 |url=https://adgeo.copernicus.org/articles/52/97/2020/ |access-date=9 November 2023|doi-access=free }} radio transmitters to send data from distant locations.

File:Example of CO2 H2S multi-GAS data.png

Monitoring changes in gas composition allows for an understanding of changes occurring in the associated volcanic system. Multi-GAS measurements of real-time CO₂/SO₂ ratios can allow detection of the pre-eruptive degassing of rising magmas, improving the prediction of volcanic activity. As magma rises beneath the surface CO₂ solubility decreases and the gas readily exsolves, leading to an increase in the CO₂/SO₂ ratio. A new input of CO₂-rich magma into a previously degassed system would also cause the CO₂/SO₂ ratio to rise, indicating changes in volcanic activity. During a two year study at Mount Etna quiescent periods had CO₂/SO₂ ratios <1, but during the lead up to an eruption values as high as 25 were seen. Magmatic or hydrothermal input can be monitored by the temporal variations in H₂S/SO₂ ratios, advancing the understanding of future eruptive behavior.{{Cite journal|last1=Moor|first1=J. Maarten de|last2=Aiuppa|first2=A.|last3=Avard|first3=G.|last4=Wehrmann|first4=H.|last5=Dunbar|first5=N.|last6=Muller|first6=C.|last7=Tamburello|first7=G.|last8=Giudice|first8=G.|last9=Liuzzo|first9=M.|last10=Moretti|first10=R.|last11=Conde|first11=V.|date=2016|title=Turmoil at Turrialba Volcano (Costa Rica): Degassing and eruptive processes inferred from high-frequency gas monitoring|url= |journal=Journal of Geophysical Research: Solid Earth|language=en|volume=121|issue=8|pages=5761–5775|doi=10.1002/2016JB013150|issn=2169-9356|pmc=5054823|pmid=27774371|bibcode=2016JGRB..121.5761D}} CO₂/H₂S ratios are used to define the characteristic gas composition of the sampled area.{{Cite journal|last1=Napoli|first1=Rossella Di|last2=Aiuppa|first2=Alessandro|last3=Allard|first3=Patrick|date=2014|title=First Multi-GAS based characterisation of the Boiling Lake volcanic gas (Dominica, Lesser Antilles)|url=https://www.annalsofgeophysics.eu/index.php/annals/article/view/6277|journal=Annals of Geophysics|language=en|volume=56|issue=5|pages=0559|doi=10.4401/ag-6277|issn=2037-416X|hdl=10447/87765|hdl-access=free}} The ratio can be a tool for understanding how the magmatic gas may have been scrubbed. Other molar ratios and gas species measured by a multi-GAS can provide information for further analysis of volcanic conditions.

Multi-GAS stations have been employed at many volcanoes all around the world and due to its simple design it can be employed by many groups, like scientists, for academic purposes, or government agencies like the USGS, that can use data for public safety reasons. In Europe and Asia volcanoes like Stromboli{{Cite journal|last1=Aiuppa|first1=Alessandro|last2=Federico|first2=Cinzia|last3=Giudice|first3=Gaetano|last4=Giuffrida|first4=Giovanni|last5=Guida|first5=Roberto|last6=Gurrieri|first6=Sergio|last7=Liuzzo|first7=Marco|last8=Moretti|first8=Roberto|last9=Papale|first9=Paolo|date=2009|title=The 2007 eruption of Stromboli volcano: Insights from real-time measurement of the volcanic gas plume CO2/SO2 ratio|url=http://www.sciencedirect.com/science/article/pii/S0377027308005313|journal=Journal of Volcanology and Geothermal Research|language=en|volume=182|issue=3|pages=221–230|doi=10.1016/j.jvolgeores.2008.09.013|bibcode=2009JVGR..182..221A|issn=0377-0273|url-access=subscription}} and Vulcano,{{Cite journal|last1=Aiuppa|first1=A.|last2=Bagnato|first2=E.|last3=Witt|first3=M. L. I.|last4=Mather|first4=T. A.|last5=Parello|first5=F.|last6=Pyle|first6=D. M.|last7=Martin|first7=R. S.|date=2007|title=Real-time simultaneous detection of volcanic Hg and SO2 at La Fossa Crater, Vulcano (Aeolian Islands, Sicily)|journal=Geophysical Research Letters|language=en|volume=34|issue=21|pages=L21307|doi=10.1029/2007GL030762|bibcode=2007GeoRL..3421307A|issn=1944-8007|doi-access=free}} Mount Yasur, Miyake-jima{{Cite journal|last1=Shinohara|first1=Hiroshi|last2=Geshi|first2=Nobuo|last3=Matsushima|first3=Nobuo|last4=Saito|first4=Genji|last5=Kazahaya|first5=Ryunosuke|date=2017|title=Volcanic gas composition changes during the gradual decrease of the gigantic degassing activity of Miyakejima volcano, Japan, 2000-2015|url=https://doi.org/10.1007/s00445-017-1105-0|journal=Bulletin of Volcanology|language=en|volume=79|issue=2|pages=21|doi=10.1007/s00445-017-1105-0|bibcode=2017BVol...79...21S|s2cid=132836899|issn=1432-0819|url-access=subscription}} and Mount Asama{{Cite journal|last1=Shinohara|first1=Hiroshi|last2=Ohminato|first2=Takao|last3=Takeo|first3=Minoru|last4=Tsuji|first4=Hiroshi|last5=Kazahaya|first5=Ryunosuke|date=2015|title=Monitoring of volcanic gas composition at Asama volcano, Japan, during 2004–2014|url=http://www.sciencedirect.com/science/article/pii/S0377027315002309|journal=Journal of Volcanology and Geothermal Research|language=en|volume=303|pages=199–208|doi=10.1016/j.jvolgeores.2015.07.022|bibcode=2015JVGR..303..199S|issn=0377-0273|url-access=subscription}} are well monitored with stations. In the Americas, Villarrica,{{Cite journal|last1=Aiuppa|first1=Alessandro|last2=Bitetto|first2=Marcello|last3=Francofonte|first3=Vincenzo|last4=Velasquez|first4=Gabriela|last5=Parra|first5=Claudia Bucarey|last6=Giudice|first6=Gaetano|last7=Liuzzo|first7=Marco|last8=Moretti|first8=Roberto|last9=Moussallam|first9=Yves|last10=Peters|first10=Nial|last11=Tamburello|first11=Giancarlo|date=2017|title=A CO2-gas precursor to the March 2015 Villarrica volcano eruption|url=https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017GC006892|journal=Geochemistry, Geophysics, Geosystems|language=en|volume=18|issue=6|pages=2120–2132|doi=10.1002/2017GC006892|bibcode=2017GGG....18.2120A|s2cid=133688817 |issn=1525-2027|url-access=subscription}} Masaya Volcano,{{Cite journal|last1=Witt|first1=M. L. I.|last2=Mather|first2=T. A.|last3=Pyle|first3=D. M.|last4=Aiuppa|first4=A.|last5=Bagnato|first5=E.|last6=Tsanev|first6=V. I.|date=2008|title=Mercury and halogen emissions from Masaya and Telica volcanoes, Nicaragua|journal=Journal of Geophysical Research: Solid Earth|language=en|volume=113|issue=B6|pages=B06203|doi=10.1029/2007JB005401|bibcode=2008JGRB..113.6203W|issn=2156-2202|doi-access=free}} Mount St. Helens,{{Cite web|title=Volcanic Gas Monitoring at Mount St. Helens|url=https://www.usgs.gov/volcanoes/mount-st-helens/volcanic-gas-monitoring-mount-st-helens?qt-science_support_page_related_con=2#qt-science_support_page_related_con|access-date=2020-10-29|website=www.usgs.gov}} and Soufrière Hills{{Cite journal|last1=Christopher|first1=Thomas|last2=Edmonds|first2=Marie|last3=Humphreys|first3=Madeleine C. S.|last4=Herd|first4=Richard A.|date=2010|title=Volcanic gas emissions from Soufrière Hills Volcano, Montserrat 1995–2009, with implications for mafic magma supply and degassing|journal=Geophysical Research Letters|language=en|volume=37|issue=19|pages=n/a|doi=10.1029/2009GL041325|bibcode=2010GeoRL..37.0E04C|issn=1944-8007|doi-access=free}} are also observed with instruments for changes in volcanic gas output.

A permanent multi-GAS installment was placed by Mount Etna's summit crater to collect real-time measurements of H₂O, CO₂, and SO₂ over a 2-year period. Data was used to correlate increasing CO₂/SO₂ ratios with rising magma beneath the edifice and associated volcanic eruptions.

A multi-GAS was emplaced in the Krýsuvík geothermal system to collect real-time time-series data of H₂O, CO₂, SO₂, and H₂S. Molar ratios were compared with local seismic data; increased gas ratio values followed episodes of increased seismicity. Degassing activity increases after ground movement due to the opening of new paths (e.g. fractures) in the crust for the gas to flow.

To help understand caldera dynamics a multi-GAS was used to measure temporal variations in volcanic gases at Yellowstone. Temporal variations coincided with atmospheric and environmental fluctuations. Molar ratios fell within a binary mixing trend.

CO₂/SO₂ molar ratios from multi-GAS measurements confirmed a previous observation that an increase in lava lake levels correlates with an increase in the CO₂/SO_{2 ratio.}{{Cite journal|last1=Bobrowski|first1=N.|last2=Giuffrida|first2=G. B.|last3=Yalire|first3=M.|last4=Lübcke|first4=P.|last5=Arellano|first5=S.|last6=Balagizi|first6=C.|last7=Calabrese|first7=S.|last8=Galle|first8=B.|last9=Tedesco|first9=D.|date=2017|title=Multi-component gas emission measurements of the active lava lake of Nyiragongo, DR Congo|url=http://www.sciencedirect.com/science/article/pii/S1464343X16302394|journal=Journal of African Earth Sciences|language=en|volume=134|pages=856–865|doi=10.1016/j.jafrearsci.2016.07.010|bibcode=2017JAfES.134..856B|issn=1464-343X}}

The DECADE project supported initiatives to set up and expand the use of permanent instrumentation for continuous CO₂, and SO₂ measurements from volcanoes.{{cite web|title=Fischer, T. P. (2013), DEep CArbon DEgassing: The Deep Carbon Observatory DECADE Initiative, Mineralogical Magazine, 77(5), 1089|url=http://minmag.geoscienceworld.org/content/gsminmag/77/5/1058.full.pdf/}} Multi-GAS systems have been set up at volcanoes such as Villarrica, Chile and Turrialba, Costa Rica.

• Prediction of volcanic activity
• Fourier-transform infrared spectroscopy
• Differential optical absorption spectroscopy
• Ultraviolet–visible spectroscopy

{{Reflist}}

• [https://www.usgs.gov/natural-hazards/volcano-hazards/methods-measure-gas-and-water-vary-depending-upon-level-volcanic USGS Volcano Hazards Program: Monitoring Gas & Water Methods]

Category:Scientific instruments

Category:Volcanology