Browsing Radiocarbon, Volume 31, Number 3 (1989) by Authors
Radiocarbon in Dissolved Organic and Inorganic Carbon from the Central North PacificDruffel, Ellen R. M.; Williams, Peter M.; Robertson, Ken; Griffin, Sheila; Jull, A. J. Timothy; Donahue, Douglas J.; Toolin, Laurence J.; Linick, T. W. (Department of Geosciences, The University of Arizona, 1989-01-01)Radiocarbon measurements are reported for dissolved organic carbon (DOC) and inorganic carbon (DIC) from seawater samples collected from the Alcyone-5 cruise in the central North Pacific Ocean in 1985. Differences between the UV-radiation techniques used here and those reported by Williams, Oeschger and Kinney (1969) to oxidize and recover the DOC from sea water are presented. UV unoxldizable DOC in these samples is discussed in a separate publication (Druffel, Williams & Suzuki,1989). We briefly discuss the penetration of the bomb 14C signal into the DOC and DIC pools. The temporal variability of Delta-14C in DIC in surface samples taken every 2-3 days is presented. Concentrations of total dissolved free (FAA) plus combined (hydrolyzable) amino acids (THAA) and total dissolved carbohydrates (TCHO) measured in the same water samples are also reported. Our main aim is to present the chemical and isotopic data from samples collected during the Alcyone-5 cruise. Detailed interpretation is published elsewhere.
Sources of Carbon to Deep-Sea CoralsGriffin, Sheila; Druffel, Ellen R. M. (Department of Geosciences, The University of Arizona, 1989-01-01)Radiocarbon measurements in deep-sea corals from the Little Bahama Bank were used to determine the source of carbon to the skeletal matrices. Specimens of Lophelia, Gerardia, Paragorgia johnsoni and Corallium noibe were sectioned according to visible growth rings and/or stem diameter. We determined that the source of carbon to the corals accreting organic matter was primarily from surface-derived sources. Those corals that accrete a calcerous skeleton were found to obtain their carbon solely from dissolved inorganic carbon (DIC) in sea water from the depth at which the corals grew. These results, in conjunction with growth-rate studies using short-lived radioisotopes, support the use of deep-sea corals to reconstruct time histories of transient and non-transient tracers at depth in the oceans.