Towards quantification of millennial ocean oxygen changes using thallium isotopes: a case study of the Holocene

This project will study how ocean oxygen content varies during the Holocene (last 11,700 years). A key research question is whether ocean oxygen levels vary with temperature. The study will use existing sediment cores from the California margin and the Arabian Sea. The investigators will carry out high-resolution analyses using a cutting-edge technique. The ultimate goal of the project is to measure whether global ocean oxygen content increased during the Holocene. The results are important as ocean oxygenation is critical for habitability of marine ecosystems. The project will support an early-career researcher and research and training opportunities for a post-doctoral scholar and an undergraduate student. Two workshops on oceanography will be designed for middle school students. Seawater thallium isotopic compositions have recently been proposed to track the global ocean oxygen. This study will construct high-resolution thallium isotope records over the Holocene for both the Arabian Sea and California margin. The results will be used to test if the global ocean oxygen content increased during the mid-late Holocene compared to early- to mid-Holocene. A second aspect of the project is to couple thallium isotopic compositions to a model to provide quantitative constraints on ocean oxygen. The results will have implications for understanding the ocean’s role in global biogeochemical cycles, especially carbon and nitrogen. New workshops on science topics related to the project research will be delivered through class visits to local middle schools. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. NSF Award ID: 2609014 | Program: 01002627DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: Yi Wang | Institution: Tulane University, NEW ORLEANS, LA | Award Amount: $366,587 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2609014 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2609014.html