Osmium is one of the rarest elements present in the oceans existing in multiple oxidation states. To date, different analytical protocols have been used to analyze seawater samples from the three ocean basins for osmium resulting in different results for each. Scientists from Woods Hole Oceanographic Institute, Dartmouth University, and the University of Hawaii propose to analyze samples collected during the two GEOTRACES intercalibration cruises to determine whether divergent results obtained for the three ocean basins is the result of inherent differences in the system or due to the different analytical protocols. The PIs would intercalibrate an osmium standard and tracer solutions, prepare "osmium free' water and assess blanks, and evaluate the effect of sampling and storage on the osmium isotopic content.
As regards broader impacts, accurate and precise osmium concentrations and isotopic ratios would provide the sciences community with a potential new tracer in marine chemistry and paleoceanography.