The fractionation between different stable isotopic species of the elements carbon and oxygen provides a powerful tool for investigation of various physical, chemical and biological processes in nature. Complex systoms involving the interaction of several such processes can be studied by combining isotope ratio measurements with other suitable data. The oceans constitute one of the most important of these systems; the distribution of carbon and oxygen in the sea is governed by a balance amongst physical, chemical and biological forces so that information on the isotopic abundances can be profitably used in oceanographic description. In this work, experimental techniques for determination of 6180 of seawater, and extraction and measurement of total dissolved inorganic carbon (EC02) from seawater and its 613C -assay are described. The assumptions involved in these methods are investigated and the associated errors discussed, in particular with regard to the mass spectrometry. The storage of oceanographic water samples between collection and analysis may allow biological activity to alter the dissolved oxygen/ carbon system. Inconsistencies in previously published work are pointed out and experiments are detailed which illustrate that temporal rCO2 and ý13C variations mirror the changes known to occur in the bacterial population of seawater stored without the addition of poison. Different types of storage vessel are investigated for preserving sample integrity and it is concluded that the importance of immediate poisoning and proper storage has been seriously underestimated in much previous work. Vater samples have been collected from areas of the Pacific and Antarctic Oceans, and analysed for 5180 of the water, >C02 and its 613C and, in some cases, pH and dissolved oxygen. The 6180 results have been taken in conjunction with conventional, hydrographic data to provide descriptions of the physical oceanography of the regions; water mass structure, and mixing has been elucidated and discussed. In the light of this, the ECO2,613C, pH and dissolved. oxygen measurements have been used to investigate the chemical and biological regimes. Comparison of the results of several different investigators in the Pacific has suggested that systematic errors may exist between directly and indirectly determined. ECO2 values. The regional oceanography deduced from this research has been in general accord with commonly accepted views derived from other studies.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:455123 |
| Date | January 1975 |
| Creators | Fallick, Anthony E. |
| Publisher | University of Glasgow |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://theses.gla.ac.uk/4136/ |
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