Oxygen isotope and Mg/Ca record of planktonic foraminifera of sediment core MD01-2390
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| Format: | Dataset Open Access |
| Langue: | en |
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PANGAEA
2006
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| _version_ | 1867167663300542464 |
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| author | Steinke, Stephan Chiu, Han-Yi Yu, Pai-Sen Shen, Chuan Chou Erlenkeuser, Helmut Löwemark, Ludvig Chen, Min-Te |
| author_facet | Steinke, Stephan Chiu, Han-Yi Yu, Pai-Sen Shen, Chuan Chou Erlenkeuser, Helmut Löwemark, Ludvig Chen, Min-Te |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | Changes in the local freshwater budget over the last 22,000 years have been estimated from a sediment core located in the southern South China Sea (SCS) using a combined approach of Mg/Ca and oxygen isotopes on the planktonic foraminifera Globigerinoides ruber (white) sensu stricto (s.s.). Core MD01-2390 (06°28,12N, 113°24,56E; water depth 1591 m) is located near the glacial paleo-river mouths of the Baram, Rajang and North Sunda/Molengraaff Rivers that drained the exposed Sunda Shelf. The delta18Oseawater record reveals lower average values (-0.96±0.18 per mil) during the Last Glacial Maximum (LGM) when compared with modern values (-0.54±0.18 per mil). Low salinity during the LGM is interpreted to reflect a higher freshwater contribution due to a greater proximity of the core site to the mouths of the Baram, Rajang and North Sunda/Molengraaff Rivers at that time. A general deglacial increasing trend in salinity due to the progressive landward displacement of the coastline during deglacial shelf flooding is punctuated by several short-term shifts towards higher and lower salinity that are likely related to abrupt changes in the intensity of the East Asian summer monsoon. Thus, the deglacial delta18Oseawater changes reflect the combined effects of sea-level-induced environmental changes on the shelf (e.g. phases of retreat and breakdown of the shelf drainage systems) and East Asian monsoon climate change. Lower salinity than at present during the Early Holocene may be attributed to an increase in summer monsoonal precipitation that is corroborated by previous marine and terrestrial studies that report a Preboreal-Early Holocene monsoon optimum in the Asian monsoon region. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_738282 |
| institution | PANGAEA |
| language | en |
| publishDate | 2006 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Oxygen isotope and Mg/Ca record of planktonic foraminifera of sediment core MD01-2390 Steinke, Stephan Chiu, Han-Yi Yu, Pai-Sen Shen, Chuan Chou Erlenkeuser, Helmut Löwemark, Ludvig Chen, Min-Te Giant piston corer; GPC; IMAGES; IMAGES VII - WEPAMA; International Marine Global Change Study; Marion Dufresne (1995); MD012390; MD01-2390; MD122; Planktic Foraminifers; South China Sea Changes in the local freshwater budget over the last 22,000 years have been estimated from a sediment core located in the southern South China Sea (SCS) using a combined approach of Mg/Ca and oxygen isotopes on the planktonic foraminifera Globigerinoides ruber (white) sensu stricto (s.s.). Core MD01-2390 (06°28,12N, 113°24,56E; water depth 1591 m) is located near the glacial paleo-river mouths of the Baram, Rajang and North Sunda/Molengraaff Rivers that drained the exposed Sunda Shelf. The delta18Oseawater record reveals lower average values (-0.96±0.18 per mil) during the Last Glacial Maximum (LGM) when compared with modern values (-0.54±0.18 per mil). Low salinity during the LGM is interpreted to reflect a higher freshwater contribution due to a greater proximity of the core site to the mouths of the Baram, Rajang and North Sunda/Molengraaff Rivers at that time. A general deglacial increasing trend in salinity due to the progressive landward displacement of the coastline during deglacial shelf flooding is punctuated by several short-term shifts towards higher and lower salinity that are likely related to abrupt changes in the intensity of the East Asian summer monsoon. Thus, the deglacial delta18Oseawater changes reflect the combined effects of sea-level-induced environmental changes on the shelf (e.g. phases of retreat and breakdown of the shelf drainage systems) and East Asian monsoon climate change. Lower salinity than at present during the Early Holocene may be attributed to an increase in summer monsoonal precipitation that is corroborated by previous marine and terrestrial studies that report a Preboreal-Early Holocene monsoon optimum in the Asian monsoon region. |
| title | Oxygen isotope and Mg/Ca record of planktonic foraminifera of sediment core MD01-2390 |
| topic | Giant piston corer; GPC; IMAGES; IMAGES VII - WEPAMA; International Marine Global Change Study; Marion Dufresne (1995); MD012390; MD01-2390; MD122; Planktic Foraminifers; South China Sea |
| url | https://doi.org/10.1594/PANGAEA.738282 |