Evidence for rapid weathering response to climatic warming during the Toarcian Oceanic Anoxic Event.
Evidence for rapid weathering response to climatic warming during the Toarcian Oceanic Anoxic Event.
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DOI：
10.1038/s41598-017-05307-y
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发表时间：
2017-07-10
影响因子：
4.6
通讯作者：
Owens JD
中科院分区：
文献类型：
--
作者：
Them TR;Gill BC;Selby D;Gröcke DR;Friedman RM;Owens JD
化学风化作用通过硅酸盐矿物的分解消耗大气中的二氧化碳，被认为可以稳定地球的长期气候。然而，在地质短时间尺度（103-105年）上，硅酸盐风化对大气pCO2水平的潜在影响仍然知之甚少。在此，我们重点研究了北美西部开阔海域沉积序列中横贯托瓦西亚海洋缺氧事件（T-OAE）的短暂气候变暖间隔。配对的锇同位素数据和数值模拟结果表明，与事件发生前的基线相比，风化速率可能增加了215%，甚至可能高达530%，这将导致大量大气二氧化碳的封存。这一过程还会增加向海洋和湖泊输送的营养物质，刺激生物生产力，并导致随后的浅水缺氧，这是T-OAE的标志。这种生物生产力的提高和缺氧将导致有机物埋藏率的提高，这将对大气二氧化碳分压水平产生额外的负反馈。因此，最初增加的二氧化碳分压水平所调节的风化作用的增强将作为直接和间接的负反馈来结束T-OAE。
Chemical weathering consumes atmospheric carbon dioxide through the breakdown of silicate minerals and is thought to stabilize Earth’s long-term climate. However, the potential influence of silicate weathering on atmospheric pCO2 levels on geologically short timescales (103–105 years) remains poorly constrained. Here we focus on the record of a transient interval of severe climatic warming across the Toarcian Oceanic Anoxic Event or T-OAE from an open ocean sedimentary succession from western North America. Paired osmium isotope data and numerical modelling results suggest that weathering rates may have increased by 215% and potentially up to 530% compared to the pre-event baseline, which would have resulted in the sequestration of significant amounts of atmospheric CO2. This process would have also led to increased delivery of nutrients to the oceans and lakes stimulating bioproductivity and leading to the subsequent development of shallow-water anoxia, the hallmark of the T-OAE. This enhanced bioproductivity and anoxia would have resulted in elevated rates of organic matter burial that would have acted as an additional negative feedback on atmospheric pCO2 levels. Therefore, the enhanced weathering modulated by initially increased pCO2 levels would have operated as both a direct and indirect negative feedback to end the T-OAE.
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影响因子：
3.9
作者：
Gerstenberger, H;Haase, G
通讯作者：
Haase, G
DOI：
10.1016/s0031-0182(99)00086-3
发表时间：
1999-10-01
影响因子：
3
作者：
Harries, PJ;Little, CTS
通讯作者：
Little, CTS
影响因子：
5.8
作者：
Cohen, AS;Coe, AL;Schwark, L
通讯作者：
Schwark, L
影响因子：
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作者：
Dera, Guillaume;Donnadieu, Yannick
通讯作者：
Donnadieu, Yannick
影响因子：
64.8
作者：
ELLAM, RM;CARLSON, RW;SHIREY, SB
通讯作者：
SHIREY, SB