Glacial water mass geometry in the South Atlantic: testing neodymium isotopes versus benthic carbon isotopes as paleo-water mass tracers

University Of Hawaii, Honolulu

Investigators

Abstract

Glacial water mass geometry in the South Atlantic: testing neodymium isotopes versus benthic carbon isotopes as paleo-water mass tracers Katharina Pahnke Lamont Doherty Earth Observatory Abstract The proposed study is designed to conduct a large-scale survey of the Holocene and Last Glacial Maximum (LGM) distribution of epsilon-Neodymium (Nd) isotopes in the South Atlantic, an area particularly sensitive to changes in the export flux of North Atlantic Deep Water, on samples used previously to generate the water mass geometry using carbon isotopes in benthic foraminifera. The project will evaluate epsilon-Nd isotopes from cores that cover a range of water depths and locations in the South Atlantic in order to develop time slice maps for the LGM and Holocene. These data will largely complement an existing database of carbon isotope data. In addition, the PI plans to put together a record of secular variations for the past ~30 ky from a core on the Ceara Rise, along the east coast of South America. All of the data will be derived from authigenic ferromanganese oxide precipitate. The data produced will provide an improved basis for the reconstruction of glacial age ocean circulation and for the linked interpretation of Late Quaternary epsilon-Nd and benthic carbon isotope records. Broader Impacts The broader impacts of this project are strong. The project will support a promising early-career woman scientist and includes funds for an undergraduate in the research. The mentoring by senior scientists as well the opportunity for the junior scientist to supervise and mentor an undergraduate are recognized as important in postdoctoral training.