Includes bibliographical references (leaves 228-270). / Subtropical ocean gyres are typically characterised by low carbon export into the deep ocean. However, due to their large area, even relatively small average carbon export may be globally significant. Strong correlations observed between deep-sea organic carbon, calcite and opal suggest that mineral phases may enhance the export and survival of organic matter as it sinks (the 'ballast effect'). However, the processes underlying these correlations are not well understood and remain key uncertainties in models that predict global carbon cycling. To better constrain carbon and mineral export from the surface ocean of subtropical gyres, radioactive disequilibria between 234Th and 238U were used to estimate fluxes of particulate organic carbon (POe), calcite and opal in the North and South Atlantic subtropical gyres.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uct/oai:localhost:11427/6452 |
| Date | January 2007 |
| Creators | Thomalla, S J |
| Contributors | Lucas, Mike, Turnewitsch, Robert |
| Publisher | University of Cape Town, Faculty of Science, Department of Oceanography |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Doctoral Thesis, Doctoral, PhD |
| Format | application/pdf |
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