The Paleocene–Eocene thermal maximum (PETM), a transient period of global warming, is considered to be an important analog for future greenhouse conditions. It was accompanied by a significant carbon cycle perturbation. Although ocean deoxygenation across the PETM is reported widely, its mechanism in the open ocean remains uncertain. Here, we present magnetic and geochemical analyses of sediments from the eastern equatorial Pacific Ocean. We found that iron fertilization during the PETM by eolian dust and volcanic eruptions fueled eastern equatorial Pacific Ocean productivity. This process led to increased organic matter degradation and oxygen consumption in intermediate waters, leading to deoxygenation. Our findings suggest that iron fertilization could be an important driver of open-ocean oxygen loss, as a side effect of global warming.

中文翻译：

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古新世-始新世热最大值期间铁肥化引起的赤道东太平洋中间水域脱氧

古新世-始新世最热期（PETM）是全球变暖的一个短暂时期，被认为是未来温室条件的重要模拟。它伴随着显着的碳循环扰动。尽管PETM的海洋脱氧现象已被广泛报道，但其在公海的机制仍不确定。在这里，我们对东赤道太平洋沉积物进行了磁性和地球化学分析。我们发现，PETM期间风尘和火山喷发对铁的施肥促进了赤道东太平洋的生产力。这一过程导致中间水域有机物降解和氧气消耗增加，导致脱氧。我们的研究结果表明，作为全球变暖的副作用，铁施肥可能是公海氧气流失的重要驱动因素。