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

University Of Southern California, Los Angeles CA

Investigators

Abstract

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.