Search results for "gas fluxes"
showing 5 items of 5 documents
Magma and volatile supply to post-collapse volcanism and block resurgence in Siwi caldera (Tanna Island, Vanuatu arc)
2011
Siwi caldera, in the Vanuatu arc (Tanna island), is a rare volcanic complex where both persistent eruptive activity (Yasur volcano) and rapid block resurgence (Yenkahe horst) can be investigated simultaneously during a post-caldera stage. Here we provide new constraints on the feeding system of this volcanic complex, based on a detailed study of the petrology, geochemistry and volatile content of Yasur-Siwi bulk-rocks and melt inclusions, combined with measurements of the chemical composition and mass fluxes of Yasur volcanic gases. Major and trace element analyses of Yasur-Siwi volcanic rocks, together with literature data for other volcanic centers, point to a single magmatic series and p…
Steam and gas emission rate from La Soufriere volcano, Guadeloupe (Lesser Antilles): implications for the magmatic and hydrothermal fluid supply duri…
2014
Since its last magmatic eruption in 1530 AD, La Soufrière andesitic volcano in Guadeloupe has displayed intense hydrothermal activity and six phreatic eruptive crises. Here we report on the first direct quantification of gas plume emissions from its summit vents,which gradually intensified during the past 20 years. Gas fluxes were determined in March 2006 and March 2012 by measuring the horizontal and vertical distributions of volcanic gas concentrations in the air-diluted plume and scaling to the speed of plume transport. Fluxes in 2006 combine realtime measurements of volcanic H2S concentrations and plume parameters with the composition of the hot (108.5 °C) fumarolic fluid at exit. Fluxe…
Strombolian eruptions and dynamics of magma degassing at Yasur Volcano (Vanuatu)
2020
Abstract Open vent basaltic volcanoes account for a substantial portion of the global atmospheric outgassing flux, largely through passive degassing and mild explosive activity. We present volcanic gas flux and composition data from Yasur Volcano, Vanuatu collected in July 2018. The average volcanic plume chemistry is characterised by a mean molar CO2/SO2 ratio of 2.14, H2O/SO2 of 148 and SO2/HCl of 1.02. The measured mean SO2 flux in the period of 6th to 9th July is 4.9 kg s−1. Therefore, the mean fluxes of the other species are 7.5 kg∙s−1 CO2, 208 kg∙s−1 H2O and 4.8 kg∙s−1 HCl. The degassing regime at Yasur volcano ranges from ‘passive’ to ‘active’ styles, with the latter including Stromb…
Large stocks of peatland carbon and nitrogen are vulnerable to permafrost thaw
2020
Significance Over many millennia, northern peatlands have accumulated large amounts of carbon and nitrogen, thus cooling the global climate. Over shorter timescales, peatland disturbances can trigger losses of peat and release of greenhouses gases. Despite their importance to the global climate, peatlands remain poorly mapped, and the vulnerability of permafrost peatlands to warming is uncertain. This study compiles over 7,000 field observations to present a data-driven map of northern peatlands and their carbon and nitrogen stocks. We use these maps to model the impact of permafrost thaw on peatlands and find that warming will likely shift the greenhouse gas balance of northern peatlands. …
CO2 flux emissions from the Earth's most actively degassing volcanoes, 2005-2015
2019
AbstractThe global carbon dioxide (CO2) flux from subaerial volcanoes remains poorly quantified, limiting our understanding of the deep carbon cycle during geologic time and in modern Earth. Past attempts to extrapolate the global volcanic CO2 flux have been biased by observations being available for a relatively small number of accessible volcanoes. Here, we propose that the strong, but yet unmeasured, CO2 emissions from several remote degassing volcanoes worldwide can be predicted using regional/global relationships between the CO2/ST ratio of volcanic gases and whole-rock trace element compositions (e.g., Ba/La). From these globally linked gas/rock compositions, we predict the CO2/ST gas…