Historical climate variability reconstructed from massive coral records in the western Indian Ocean

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dc.contributor.advisorReason, Chrisen_ZA
dc.contributor.advisorZinke, Jensen_ZA
dc.contributor.authorNicolas, Jean Vincent Arnauden_ZA
dc.date.accessioned2014-11-28T09:55:13Z
dc.date.available2014-11-28T09:55:13Z
dc.date.issued2012en_ZA
dc.descriptionIncludes bibliographical references.en_ZA
dc.description.abstractCoral δ¹⁸O and Sr/Ca records from massive corals in the western Indian Ocean (WIO) are used to establish the heterogeneous distribution of warming rates across the tropical and subtropical regions and to investigate if it corresponds with that from instrumental sea surface temperatures (SSTs). The coral records correlate with instrumental data better on monthly time scales compared to annual time scales. Coral thermal stress was assessed by the Degree Heating Months (DHM) technique and even though the coral DHM aligns quite well with instrumental DHM, the values from coral data are generally 2-3 times greater in magnitude than the DHM values from instrumental data. It was found that the accumulated thermal stress, calculated from coral and instrumental data, for the majority of the tropical and subtropical WIO sites has been increasing since the 1970’s. From 1870 to 1995, both the tropics and the subtropics have been warming in general, although with different and varying rates as recorded by the coral and the instrumental SSTs. It was further revealed that both the tropical and the subtropical WIO warmed during the summer and winter periods during 1870-1995. On longer time scales, the relationship between the coral records in the WIO and climate indices showed a significant interannual variability approximately centered at periods 3-6 years, indicating a probable link with ENSO and IOD. The extent to which coral reefs from different sites in the WIO are prepared to survive climate change based on historical SST variability and intensity of warming rates are described. It could therefore be suggested that some corals may be more favoured to survive warming climate compared to others because corals in the WIO are located in different oceanographic conditions and experience different climatic variations.en_ZA
dc.identifier.apacitationNicolas, J. V. A. (2012). <i>Historical climate variability reconstructed from massive coral records in the western Indian Ocean</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Oceanography. Retrieved from http://hdl.handle.net/11427/9811en_ZA
dc.identifier.chicagocitationNicolas, Jean Vincent Arnaud. <i>"Historical climate variability reconstructed from massive coral records in the western Indian Ocean."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Oceanography, 2012. http://hdl.handle.net/11427/9811en_ZA
dc.identifier.citationNicolas, J. 2012. Historical climate variability reconstructed from massive coral records in the western Indian Ocean. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Nicolas, Jean Vincent Arnaud AB - Coral δ¹⁸O and Sr/Ca records from massive corals in the western Indian Ocean (WIO) are used to establish the heterogeneous distribution of warming rates across the tropical and subtropical regions and to investigate if it corresponds with that from instrumental sea surface temperatures (SSTs). The coral records correlate with instrumental data better on monthly time scales compared to annual time scales. Coral thermal stress was assessed by the Degree Heating Months (DHM) technique and even though the coral DHM aligns quite well with instrumental DHM, the values from coral data are generally 2-3 times greater in magnitude than the DHM values from instrumental data. It was found that the accumulated thermal stress, calculated from coral and instrumental data, for the majority of the tropical and subtropical WIO sites has been increasing since the 1970’s. From 1870 to 1995, both the tropics and the subtropics have been warming in general, although with different and varying rates as recorded by the coral and the instrumental SSTs. It was further revealed that both the tropical and the subtropical WIO warmed during the summer and winter periods during 1870-1995. On longer time scales, the relationship between the coral records in the WIO and climate indices showed a significant interannual variability approximately centered at periods 3-6 years, indicating a probable link with ENSO and IOD. The extent to which coral reefs from different sites in the WIO are prepared to survive climate change based on historical SST variability and intensity of warming rates are described. It could therefore be suggested that some corals may be more favoured to survive warming climate compared to others because corals in the WIO are located in different oceanographic conditions and experience different climatic variations. DA - 2012 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2012 T1 - Historical climate variability reconstructed from massive coral records in the western Indian Ocean TI - Historical climate variability reconstructed from massive coral records in the western Indian Ocean UR - http://hdl.handle.net/11427/9811 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/9811
dc.identifier.vancouvercitationNicolas JVA. Historical climate variability reconstructed from massive coral records in the western Indian Ocean. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Oceanography, 2012 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/9811en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Oceanographyen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherApplied Marine Scienceen_ZA
dc.titleHistorical climate variability reconstructed from massive coral records in the western Indian Oceanen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMScen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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