Operation of A National Ocean Sciences Accelerator Mass Spectrometry Facility at The Woods Hole Oceanographic Institution

Woods Hole Oceanographic Institution, Woods Hole MA

Investigators

Abstract

The National Ocean Sciences Accelerator Mass Spectrometry facility (NOSAMS) offers state of-the-art 14C (radiocarbon) measurements in a wide range of natural sample types, including seawater, groundwater, carbonates, bulk sediments, soils, and organic carbon. Measurements of radiocarbon in natural samples provide a unique and powerful set of tools for ocean and earth science. The 14C half-life (time it takes for half of the atoms in a sample to decay) of 5700 years can be used to date carbon-bearing samples as old as 50,000 years, and to study the time scales of ocean circulation and mixing, the timing of climate changes, and the details of modern carbon cycling. Radiocarbon measurements are used in many branches of ocean research including physical oceanography, biogeochemistry, paleooceanography, and climate change. The research enabled by the NOSAMS measurements addresses questions that are important to society: among them issues of past and future global climate change, local and regional environmental impacts, and the development of natural resources. In addition to supporting socially relevant research, NOSAMS will play an important role in training and mentorship of graduate students and postdoctoral researchers. NOSAMS promotes general public understanding of radiocarbon and related scientific issues through web sites and in hosting tours for the visiting public. The Division of Ocean Sciences at NSF provides base support for the operation and maintenance of the National Ocean Sciences Accelerator Mass Spectrometer (NOSAMS) facility. The facility provides natural level radiocarbon dating services to the oceanographic community. Radiocarbon is an important tool in climate, carbon cycle, and biogeochemical science. It is useful as a chronometer covering the past ~50,000 years, it is a diagnostic of past changes in the carbon cycle, it serves as a tracer of ocean circulation, and it is a probe for carbon flow in the environment. Thus radiocarbon measurements are used in many sectors of ocean science research ranging from paleoceanography, physical oceanography, biogeochemistry, and climate change science. Current environmental level radiocarbon measurements require careful sample processing that minimizes contamination risk and other experimental artifacts, and the use of Accelerator Mass Spectrometry (AMS) systems. Consequently, it is advantageous to have and maintain a central facility that serves the broader ocean sciences community by making such measurements and acting as a center of expertise, as well as sustaining and advancing the state-of-the-art in such measurements. The PI?s propose to continue operations for another five years, while gradually increasing the numbers of samples analyzed each year, improving the accuracy and precision of measurements, and expanding the methodology in new directions. They also plan to continue to improve and develop new radiocarbon measurement capabilities and propose to expand the portfolio of services offered to the community. Recent advances include pioneering innovative techniques such as the REDICS (Rapid Extraction of Dissolved Inorganic Carbon System) and the Ramped Pyrolysis System, both of which allow NOSAMS to maintain its competitive edge. Proposed research includes new inroads into compound specific and compound class radiocarbon analysis, as well as extending analyses to smaller samples. 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.