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| Sulpis, Olivier; Boudreau, Bernard P.; Mucci, Alfonso; Jenkins, Chris; Trossman, David S.; Arbic, Brian K.; Key, Robert M.. |
| Oceanic uptake of anthropogenic CO2 leads to decreased pH, carbonate ion concentration, and saturation state with respect to CaCO3 minerals, causing increased dissolution of these minerals at the deep seafloor. This additional dissolution will figure prominently in the neutralization of man-made CO2 . However, there has been no concerted assessment of the current extent of anthropogenic CaCO3 dissolution at the deep seafloor. Here, recent databases of bottom-water chemistry, benthic currents, and CaCO3 content of deep-sea sediments are combined with a rate model to derive the global distribution of benthic calcite dissolution rates and obtain primary confirmation of an anthropogenic component. By comparing preindustrial with present-day rates, we determine... |
| Tipo: Text |
Palavras-chave: Ocean acidification; Seafloor; CaCO3; Dissolution; Anthropogenic CO2. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00675/78677/80887.pdf |
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| Thibodeau, Benoit; De Vernal, Anne; Hillaire-marcel, Claude; Mucci, Alfonso. |
| The impact of human activities on Earth's climate is still subject to debate and the pattern of a sharp recent global temperature increase contrasting with much lesser variable temperatures during preceding centuries has often been challenged, partly due to the lack of unquestionable evidence. In this paper, oxygen isotope compositions of benthic foraminifer shells recovered from sediments of the Lower St. Lawrence Estuary and the Gulf are used to reconstruct temperature changes in a water mass originating from similar to 400 m deep North Atlantic waters. The data demonstrate that the 1.7 +/- 0.3 degrees C warming measured during the last century corresponds to a delta(18)O shift of 0.4 +/- 0.05 parts per thousand, encompassing the temperature effect and... |
| Tipo: Text |
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| Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00231/34176/32910.pdf |
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