230Th and 231Pa on GEOTRACES GA03, the U.S. GEOTRACES North Atlantic transect, and implications for modern and paleoceanographic chemical fluxes ...

• Main Authors: Hayes, Christopher T., Anderson, Robert F., Fleisher, Martin Q., Huang, Kuo-Fang, Robinson, Laura F., Lu, Yanbin, Cheng, Hai, Edwards, R. Lawrence, Moran, S. Bradley
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Columbia University 2014
• Subjects: Submarine geology; Chemical oceanography; Mineralogy; North Atlantic
• Online Access: https://dx.doi.org/10.7916/d8ws8sn3; https://academiccommons.columbia.edu/doi/10.7916/D8WS8SN3

The long-lived uranium decay products 230Th and 231Pa are widely used as quantitative tracers of adsorption to sinking particles (scavenging) in the ocean by exploiting the principles of radioactive disequilibria. Because of their preservation in the Pleistocene sediment record and through largely untested assumptions about their chemical behavior in the water column, the two radionuclides have also been used as proxies for a variety of chemical fluxes in the past ocean. This includes the vertical flux of particulate matter to the seafloor, the lateral flux of insoluble elements to continental margins (boundary scavenging), and the southward flux of water out of the deep North Atlantic. In a section of unprecedented vertical and zonal resolution, the distributions of 230Th and 231Pa across the North Atlantic shed light on the marine cycling of these radionuclides and further inform their use as tracers of chemical flux. Enhanced scavenging intensities are observed in benthic layers of resuspended sediments ...