李明松 --北京大学--动态

The end-Permian mass extinction event (ca. 252 Mya) is the most-severe biodiversity loss in Earth’s history and is globally recognized by a rapid negative carbon isotope excursion. The trigger of this event, however, remains controversial. New paired terrestrial and marine compound-specific carbon isotope records may provide clues for this enigma. By comparing observed data to results from an isotope-enabled Earth system model, we find that a massive and rapid, predominantly volcanic CO2 emission during the Siberian Traps volcanism is likely the trigger for the carbon isotope excursion and the severe mass extinction. Our findings provide quantitative constraints of how a massive and rapid increase in CO2 may have influenced the marine ecosystem 252 Mya.The end-Permian mass extinction event (∼252 Mya) is associated with one of the largest global carbon cycle perturbations in the Phanerozoic and is thought to be triggered by the Siberian Traps volcanism. Sizable carbon isotope excursions (CIEs) have been found at numerous sites around the world, suggesting massive quantities of 13C-depleted CO2 input into the ocean and atmosphere system. The exact magnitude and cause of the CIEs, the pace of CO2 emission, and the total quantity of CO2, however, remain poorly known. Here, we quantify the CO2 emission in an Earth system model based on new compound-specific carbon isotope records from the Finnmark Platform and an astronomically tuned age model. By quantitatively comparing the modeled surface ocean pH and boron isotope pH proxy, a massive (∼36,000 Gt C) and rapid emission (∼5 Gt C yr−1) of largely volcanic CO2 source (∼−15‰) is necessary to drive the observed pattern of CIE, the abrupt decline in surface ocean pH, and the extreme global temperature increase. This suggests that the massive amount of greenhouse gases may have pushed the Earth system toward a critical tipping point, beyond which extreme changes in ocean pH and temperature led to irreversible mass extinction. The comparatively amplified CIE observed in higher plant leaf waxes suggests that the surface waters of the Finnmark Platform were likely out of equilibrium with the initial massive centennial-scale release of carbon from the massive Siberian Traps volcanism, supporting the rapidity of carbon injection. Our modeling work reveals that carbon emission pulses are accompanied by organic carbon burial, facilitated by widespread ocean anoxia.All data presented in this study are available in the supporting information. The code necessary to run the cGENIE model is available at https://github.com/derpycode/cgenie.muffin, and all model outputs and instructions to replicate the model results are accessible at https://zenodo.org/record/4543684.

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李明松与合作者研究发现西伯利亚火山岩省大量快速碳排放导致二叠纪末生物大灭绝【北京大学新闻网】

http://news.pku.edu.cn/jxky/54fafa939c8645ff923b1eb50b4ae2a7.htm

我院研究发现二叠纪末生物大灭绝原因：西伯利亚火山岩省大量快速的碳排放【北京大学地球与空间科学学院】

https://sess.pku.edu.cn/xwzx/xydt/356286.htm

史上最大物种灭绝罪魁祸首找到了：火山二氧化碳，海水被酸化【澎湃新闻】【科学网】

https://www.thepaper.cn/newsDetail_forward_14391612

http://news.sciencenet.cn/htmlnews/2021/9/464658.shtm

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Volcanic eruptions that caused Permian mass extinction also brought huge spike in global temperatures 【Courthouse News Service】

https://www.courthousenews.com/volcanic-eruptions-that-caused-permian-mass-extinction-also-brought-huge-spike-in-global-temperatures/