EAGER: Preliminary Investigation of the Stott and Timmermann Hypothesis that Hydrothermal Carbon Fluxes Influenced Glacial/Interglacial DELTA 14C Variability

大量研究试图解释冰川/间冰期大气二氧化碳(二氧化碳)循环是通过将二氧化碳转移到深海或从深海转移二氧化碳的海洋过程来实现的。虽然研究继续探索这种机制，但最近的研究引入了新的观察结果，也需要考虑地质过程。最近的一个结合了地质过程的假说(斯托特和蒂默曼，2011年)提出，固定在高纬度的海洋温度的变化调节太平洋中等深度的二氧化碳水合物的稳定性，从而调节沉积在覆盖热液系统的沉积物中的富含二氧化碳的流体的积累和释放。然而，如果不能从西太平洋已知热液系统附近的地点获得岩心，就不可能充分检验这一假设。这个热切的项目由共同撰写这篇概念论文的南加州大学的教职员工领导，将资助与一个德国科学家团队的合作，收集位于米迪瑙岛附近的西热带太平洋的沉积物岩芯。这些材料应该能够测试有争议的热液二氧化碳假说。如果旧的碳信号的地质来源能够被识别出来，并最终与水柱信号联系在一起，它可能会改变我们对固体地球和气候之间联系的看法。资金支持首席调查员研究小组的两名成员参加研究考察，并根据岩心生成关键的初步数据。更广泛的影响包括国际合作和对南加州大学一名研究生的部分支持。

A large number of studies have sought explanations for glacial/interglacial atmospheric carbon dioxide (CO2) cycles via ocean processes that transfer CO2 to/from the deep ocean. While research continues to pursue such mechanisms, recent studies have introduced new observations that require consideration of geologic processes as well. One recent hypothesis that incorporates geologic processes (Stott and Timmermann, 2011) posited that changes in ocean temperatures, which are fixed at high latitudes, regulate CO2-hydrate stability at intermediate depths in the Pacific Ocean and in doing so, modulate the accumulation and release of CO2-rich fluids that accumulate within the sediments that blanket hydrothermal systems. However, without the availability of cores from the sites near known hydrothermal systems in the western Pacific, it has not been possible to adequately test this hypothesis. This EAGER project, led by the faculty member at the University of Southern California who co-authored the concept paper, will fund collaboration with a team of German scientists to collect sediment cores from the western tropical Pacific, near Mindinao. These materials should enable testing of the controversial hydrothermal CO2 hypothesis. If a geologic source for the old carbon signal could be identified and conclusively linked to the water column signals, it could potentially transform the way we think of the connections between the solid Earth and climate. Funding supports participation in the research expedition for two members of the principal investigator's research group, along with generation of key preliminary data from the cores. Broader impacts include international collaborations and partial support of a graduate student at the University of Southern California.