Dynamic model constraints on oxygen-17 depletion in atmospheric O 2 after a snowball Earth
A large perturbation in atmospheric CO2 and O2 or bioproductivity will result in a drastic pulse of 17O change in atmospheric O2, as seen in the Marinoan Oxygen-17 Depletion (MOSD) event in the immediate aftermath of a global deglaciation 635 Mya. The exact nature of the perturbation, however, is de...
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ftlouisianastuir:oai:digitalcommons.lsu.edu:geo_pubs-1060 2023-06-11T04:17:12+02:00 Dynamic model constraints on oxygen-17 depletion in atmospheric O 2 after a snowball Earth Cao, Xiaobin Bao, Huiming 2013-09-03T07:00:00Z application/pdf https://digitalcommons.lsu.edu/geo_pubs/61 https://doi.org/10.1073/pnas.1302972110 https://digitalcommons.lsu.edu/context/geo_pubs/article/1060/viewcontent/61.pdf unknown LSU Digital Commons https://digitalcommons.lsu.edu/geo_pubs/61 doi:10.1073/pnas.1302972110 https://digitalcommons.lsu.edu/context/geo_pubs/article/1060/viewcontent/61.pdf Faculty Publications Non-mass-dependent Photochemical reaction Postglacial cap carbonate Stratosphere text 2013 ftlouisianastuir https://doi.org/10.1073/pnas.1302972110 2023-05-28T18:24:25Z A large perturbation in atmospheric CO2 and O2 or bioproductivity will result in a drastic pulse of 17O change in atmospheric O2, as seen in the Marinoan Oxygen-17 Depletion (MOSD) event in the immediate aftermath of a global deglaciation 635 Mya. The exact nature of the perturbation, however, is debated. Here we constructed a coupled, four-box, and quick-response biosphere-atmosphere model to examine both the steady state and dynamics of the MOSD event. Our model shows that the ultra-high CO2 concentrations proposed by the "snowball' Earth hypothesis produce a typical MOSD duration of less than 106 y and a magnitude of 17O depletion reaching approximately -35‰. Both numbers are in remarkable agreement with geological constraints from South China and Svalbard. Moderate CO2 and low O2 concentration (e.g., 3,200 parts per million by volume and 0.01 bar, respectively) could produce distinct sulfate 17O depletion only if postglacial marine bioproductivity was impossibly low. Our dynamic model also suggests that a snowball in which the ocean is isolated from the atmosphere by a continuous ice cover may be distinguished from one in which cracks in the ice permit ocean-atmosphere exchange only if partial pressure of atmospheric O2 is larger than 0.02 bar during the snowball period and records of weathering-derived sulfate are available for the very first few tens of thousands of years after the onset of the meltdown. In any case, a snowball Earth is a precondition for the observed MOSD event. Text Svalbard LSU Digital Commons (Louisiana State University) Svalbard Proceedings of the National Academy of Sciences 110 36 14546 14550 |
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LSU Digital Commons (Louisiana State University) |
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Non-mass-dependent Photochemical reaction Postglacial cap carbonate Stratosphere |
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Non-mass-dependent Photochemical reaction Postglacial cap carbonate Stratosphere Cao, Xiaobin Bao, Huiming Dynamic model constraints on oxygen-17 depletion in atmospheric O 2 after a snowball Earth |
topic_facet |
Non-mass-dependent Photochemical reaction Postglacial cap carbonate Stratosphere |
description |
A large perturbation in atmospheric CO2 and O2 or bioproductivity will result in a drastic pulse of 17O change in atmospheric O2, as seen in the Marinoan Oxygen-17 Depletion (MOSD) event in the immediate aftermath of a global deglaciation 635 Mya. The exact nature of the perturbation, however, is debated. Here we constructed a coupled, four-box, and quick-response biosphere-atmosphere model to examine both the steady state and dynamics of the MOSD event. Our model shows that the ultra-high CO2 concentrations proposed by the "snowball' Earth hypothesis produce a typical MOSD duration of less than 106 y and a magnitude of 17O depletion reaching approximately -35‰. Both numbers are in remarkable agreement with geological constraints from South China and Svalbard. Moderate CO2 and low O2 concentration (e.g., 3,200 parts per million by volume and 0.01 bar, respectively) could produce distinct sulfate 17O depletion only if postglacial marine bioproductivity was impossibly low. Our dynamic model also suggests that a snowball in which the ocean is isolated from the atmosphere by a continuous ice cover may be distinguished from one in which cracks in the ice permit ocean-atmosphere exchange only if partial pressure of atmospheric O2 is larger than 0.02 bar during the snowball period and records of weathering-derived sulfate are available for the very first few tens of thousands of years after the onset of the meltdown. In any case, a snowball Earth is a precondition for the observed MOSD event. |
format |
Text |
author |
Cao, Xiaobin Bao, Huiming |
author_facet |
Cao, Xiaobin Bao, Huiming |
author_sort |
Cao, Xiaobin |
title |
Dynamic model constraints on oxygen-17 depletion in atmospheric O 2 after a snowball Earth |
title_short |
Dynamic model constraints on oxygen-17 depletion in atmospheric O 2 after a snowball Earth |
title_full |
Dynamic model constraints on oxygen-17 depletion in atmospheric O 2 after a snowball Earth |
title_fullStr |
Dynamic model constraints on oxygen-17 depletion in atmospheric O 2 after a snowball Earth |
title_full_unstemmed |
Dynamic model constraints on oxygen-17 depletion in atmospheric O 2 after a snowball Earth |
title_sort |
dynamic model constraints on oxygen-17 depletion in atmospheric o 2 after a snowball earth |
publisher |
LSU Digital Commons |
publishDate |
2013 |
url |
https://digitalcommons.lsu.edu/geo_pubs/61 https://doi.org/10.1073/pnas.1302972110 https://digitalcommons.lsu.edu/context/geo_pubs/article/1060/viewcontent/61.pdf |
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Svalbard |
geographic_facet |
Svalbard |
genre |
Svalbard |
genre_facet |
Svalbard |
op_source |
Faculty Publications |
op_relation |
https://digitalcommons.lsu.edu/geo_pubs/61 doi:10.1073/pnas.1302972110 https://digitalcommons.lsu.edu/context/geo_pubs/article/1060/viewcontent/61.pdf |
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https://doi.org/10.1073/pnas.1302972110 |
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Proceedings of the National Academy of Sciences |
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110 |
container_issue |
36 |
container_start_page |
14546 |
op_container_end_page |
14550 |
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1768376130636611584 |