Diurnal variations in the isotopic composition of dissolved inorganic carbon in seawater from coral reef environments |
| |
Authors: | Jon N Weber |
| |
Institution: | Pennsylvania State University, University Park, Pennsylvania 16802 USA; Marine Sciences Research Laboratory and Department of Biology Memorial University, St. John''s, Newfoundland, Canada |
| |
Abstract: | The isotopic composition of total dissolved inorganic carbon in seawater was determined as a function of time of day in coral reef environments at Saipan, Abaiang Atoll, Tahiti, Florida and Heron Island on the Great Barrier Reef of Australia. At each locality water collected during the day was enriched in 13C with respect to water collected at night. The form and magnitude of the diurnal cycles is dependent upon the ratio of local biomass to local water mass and on the degree of exchange between local water mass and the open ocean reservoir. Comparison of open and closed system models is made using computer generated δ13C vs. time curves to illustrate modulation by the tidal cycle of the simple diurnal variation in a closed system. The results are of geochemical significance in that the δ13C of CaCO3 precipitated in certain environments is dependent on the time of crystallization. This must be taken into account in isotope ratio studies of both plant and animal secreted carbonates which are preferentially precipitated during certain periods of the day. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|