CO₂ flux emissions from the Earth's most actively degassing volcanoes, 2005-2015.

ABSTRACT: The 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/S_T 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/S_T gas ratio of 34 top-degassing remote volcanoes with no available gas measurements. By scaling to volcanic SO₂ fluxes from a global catalogue, we estimate a cumulative "unmeasured" CO₂ output of 11.4?±?1.1 Mt/yr (or 0.26?±?0.02·10¹²?mol/yr). In combination with the measured CO₂ output of 27.4?±?3.6 Mt/yr (or 0.62?±?0.08·10¹²?mol/yr), our results constrain the time-averaged (2005-2015) cumulative CO₂ flux from the Earth's 91 most actively degassing subaerial volcanoes at 38.7?±?2.9 Mt/yr (or 0.88?±?0.06·10¹²?mol/yr).

SUBMITTER: Aiuppa A 

PROVIDER: S-EPMC6443792 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature