Lages J., Moussallam Yves, Bani Philipson, Peters N., Aiuppa A., Bitetto M., Giudice G. (2020). First in-situ measurements of plume chemistry at Mount Garet Volcano, Island of Gaua (Vanuatu). Applied Sciences, 10 (20), 7293 [15p.].
Titre du document
First in-situ measurements of plume chemistry at Mount Garet Volcano, Island of Gaua (Vanuatu)
Année de publication
2020
Auteurs
Lages J., Moussallam Yves, Bani Philipson, Peters N., Aiuppa A., Bitetto M., Giudice G.
Source
Applied Sciences, 2020,
10 (20), 7293 [15p.]
Recent volcanic gas compilations have urged the need to expand in-situ plume measurements to poorly studied, remote volcanic regions. Despite being recognized as one of the main volcanic epicenters on the planet, the Vanuatu arc remains poorly characterized for its subaerial emissions and their chemical imprints. Here, we report on the first plume chemistry data for Mount Garet, on the island of Gaua, one of the few persistent volatile emitters along the Vanuatu arc. Data were collected with a multi-component gas analyzer system (multi-GAS) during a field campaign in December 2018. The average volcanic gas chemistry is characterized by mean molar CO2/SO2, H2O/SO2, H2S/SO2 and H-2/SO2 ratios of 0.87, 47.2, 0.13 and 0.01, respectively. Molar proportions in the gas plume are estimated at 95.9 +/- 11.6, 1.8 +/- 0.5, 2.0 +/- 0.01, 0.26 +/- 0.02 and 0.06 +/- 0.01, for H2O, CO2, SO2, H2S and H-2. Using the satellite-based 10-year (2005-2015) averaged SO2 flux of similar to 434 t d(-1) for Mt. Garet, we estimate a total volatile output of about 6482 t d(-1) (CO2 similar to 259 t d(-1); H2O similar to 5758 t d(-1); H2S similar to 30 t d(-1); H-2 similar to 0.5 t d(-1)). This may be representative of a quiescent, yet persistent degassing period at Mt. Garet; whilst, as indicated by SO2 flux reports for the 2009-2010 unrest, emissions can be much higher during eruptive episodes. Our estimated emission rates and gas composition for Mount Garet provide insightful information on volcanic gas signatures in the northernmost part of the Vanuatu Arc Segment. The apparent CO2-poor signature of high-temperature plume degassing at Mount Garet raises questions on the nature of sediments being subducted in this region of the arc and the possible role of the slab as the source of subaerial CO2. In order to better address the dynamics of along-arc volatile recycling, more volcanic gas surveys are needed focusing on northern Vanuatu volcanoes.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020]
;
Géophysique interne [066]
Description Géographique
VANUATU
Localisation
Fonds IRD [F B010079931]
Identifiant IRD
fdi:010079931
