Environmental reconstructions of the upper 500 m of the southern Indian Ocean over the last 40 ka using Radiolarian (Protista) proxies
In 2007, we demonstrated that radiolarians are proxies for a wide range of oceanic physico-chemical properties from the surface to depths of up to 500 m below sea level. In this study, our results are refined and Correspondence Analysis (CA) scores derived from census counts of radiolarian subfossil...
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ftanucanberra:oai:digitalcollections.anu.edu.au:1885/67084 2023-05-15T13:56:44+02:00 Environmental reconstructions of the upper 500 m of the southern Indian Ocean over the last 40 ka using Radiolarian (Protista) proxies Rogers, John De Deckker, Patrick 2015-12-10T23:24:05Z http://hdl.handle.net/1885/67084 unknown Pergamon-Elsevier Ltd 0277-3791 http://hdl.handle.net/1885/67084 Quaternary Science Reviews Journal article 2015 ftanucanberra 2015-12-21T23:43:58Z In 2007, we demonstrated that radiolarians are proxies for a wide range of oceanic physico-chemical properties from the surface to depths of up to 500 m below sea level. In this study, our results are refined and Correspondence Analysis (CA) scores derived from census counts of radiolarian subfossils from southern Indian Ocean core-tops are correlated with the physico-chemical properties of the region obtained from the 2005 World Ocean Database.Calibration and regression techniques are employed to reconstruct palaeoenvironmental conditions spanning the last 40 ka for four Indian Ocean cores MD88-769 [46°04'S 90°06'E], MD88-770 [46°01'S 96°27'E], MD94-102 [43°30'S 79°50'E], and MD94-103 [45°35'S 86°31'E], all from close to the Southeast Indian Ridge. For the first time, reconstructions of temperature, salinity, dissolved oxygen, and the silicate, nitrate, and phosphate concentrations for a range of water depths are proved possible.Changes of the oceanic environment and the movement of water masses over the last 40 ka, as suggested by these reconstructions, are discussed. During Marine Isotope Stages 2 and 3 (MIS-2 and MIS-3), the water column at some of the core sites has similar characteristics to the waters south of the Polar Front today. At the MIS-1/MIS-2 transition, the development of the Subantarctic Mode Water is apparent. Temperature reconstructions include evidence of the Antarctic Cold Reversal and the Holocene Optimum. Article in Journal/Newspaper Antarc* Antarctic Australian National University: ANU Digital Collections Antarctic Indian Southeast Indian Ridge ENVELOPE(110.000,110.000,-50.000,-50.000) The Antarctic |
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Australian National University: ANU Digital Collections |
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ftanucanberra |
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description |
In 2007, we demonstrated that radiolarians are proxies for a wide range of oceanic physico-chemical properties from the surface to depths of up to 500 m below sea level. In this study, our results are refined and Correspondence Analysis (CA) scores derived from census counts of radiolarian subfossils from southern Indian Ocean core-tops are correlated with the physico-chemical properties of the region obtained from the 2005 World Ocean Database.Calibration and regression techniques are employed to reconstruct palaeoenvironmental conditions spanning the last 40 ka for four Indian Ocean cores MD88-769 [46°04'S 90°06'E], MD88-770 [46°01'S 96°27'E], MD94-102 [43°30'S 79°50'E], and MD94-103 [45°35'S 86°31'E], all from close to the Southeast Indian Ridge. For the first time, reconstructions of temperature, salinity, dissolved oxygen, and the silicate, nitrate, and phosphate concentrations for a range of water depths are proved possible.Changes of the oceanic environment and the movement of water masses over the last 40 ka, as suggested by these reconstructions, are discussed. During Marine Isotope Stages 2 and 3 (MIS-2 and MIS-3), the water column at some of the core sites has similar characteristics to the waters south of the Polar Front today. At the MIS-1/MIS-2 transition, the development of the Subantarctic Mode Water is apparent. Temperature reconstructions include evidence of the Antarctic Cold Reversal and the Holocene Optimum. |
format |
Article in Journal/Newspaper |
author |
Rogers, John De Deckker, Patrick |
spellingShingle |
Rogers, John De Deckker, Patrick Environmental reconstructions of the upper 500 m of the southern Indian Ocean over the last 40 ka using Radiolarian (Protista) proxies |
author_facet |
Rogers, John De Deckker, Patrick |
author_sort |
Rogers, John |
title |
Environmental reconstructions of the upper 500 m of the southern Indian Ocean over the last 40 ka using Radiolarian (Protista) proxies |
title_short |
Environmental reconstructions of the upper 500 m of the southern Indian Ocean over the last 40 ka using Radiolarian (Protista) proxies |
title_full |
Environmental reconstructions of the upper 500 m of the southern Indian Ocean over the last 40 ka using Radiolarian (Protista) proxies |
title_fullStr |
Environmental reconstructions of the upper 500 m of the southern Indian Ocean over the last 40 ka using Radiolarian (Protista) proxies |
title_full_unstemmed |
Environmental reconstructions of the upper 500 m of the southern Indian Ocean over the last 40 ka using Radiolarian (Protista) proxies |
title_sort |
environmental reconstructions of the upper 500 m of the southern indian ocean over the last 40 ka using radiolarian (protista) proxies |
publisher |
Pergamon-Elsevier Ltd |
publishDate |
2015 |
url |
http://hdl.handle.net/1885/67084 |
long_lat |
ENVELOPE(110.000,110.000,-50.000,-50.000) |
geographic |
Antarctic Indian Southeast Indian Ridge The Antarctic |
geographic_facet |
Antarctic Indian Southeast Indian Ridge The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Quaternary Science Reviews |
op_relation |
0277-3791 http://hdl.handle.net/1885/67084 |
_version_ |
1766264313317687296 |