High resolution study of sediment core GeoB3606-1
Based on a high-resolution analysis of the diatom signal and biogenic bulk components at site GeoB3606-1 (25°S, off Namibia), we describe rapid palaeoceanographic changes in the Benguela Upwelling System (BUS) from early MIS 3 through to the early Holocene (55 000 to 7 000 14C yr BP). Coastal upwell...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.779190 2024-09-15T17:48:02+00:00 High resolution study of sediment core GeoB3606-1 Romero, Oscar E Mollenhauer, Gesine Schneider, Ralph R Wefer, Gerold LATITUDE: -25.466667 * LONGITUDE: 13.083333 * DATE/TIME START: 1996-01-15T00:00:00 * DATE/TIME END: 1996-01-15T00:00:00 2003 application/zip, 4 datasets https://doi.pangaea.de/10.1594/PANGAEA.779190 https://doi.org/10.1594/PANGAEA.779190 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.779190 https://doi.org/10.1594/PANGAEA.779190 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess Supplement to: Romero, Oscar E; Mollenhauer, Gesine; Schneider, Ralph R; Wefer, Gerold (2003): Oscillations of the siliceous imprint in the central Benguela Upwelling System from MIS3 through the early Holocene: the influence of the Southern Ocean. Journal of Quaternary Science, 18(8), 733-743, https://doi.org/10.1002/jqs.789 Center for Marine Environmental Sciences GeoB GeoB3606-1 Geosciences University of Bremen Gravity corer (Kiel type) M34/1 MARUM Meteor (1986) Northern Cape Basin SL dataset publication series 2003 ftpangaea https://doi.org/10.1594/PANGAEA.77919010.1002/jqs.789 2024-07-24T02:31:21Z Based on a high-resolution analysis of the diatom signal and biogenic bulk components at site GeoB3606-1 (25°S, off Namibia), we describe rapid palaeoceanographic changes in the Benguela Upwelling System (BUS) from early MIS 3 through to the early Holocene (55 000 to 7 000 14C yr BP). Coastal upwelling strongly varied at 25°S from MIS 3 through to MIS 2. The abrupt decrease in the accumulation rate of biogenic silica and diatoms from MIS 3 into MIS 2 records rapid oceanographic changes in the BUS off Namibia. During MIS 3, leakage of excess H4SiO4 acid from the Southern Ocean into low-latitude surface waters, as indicated by the occurrence of Antarctic diatoms, enhanced the production of spores of Chaetoceros at the expense of calcareous phytoplankton. Furthermore, shallower Antarctic Intermediate Water (AAIW) would have enriched the thermocline off Namibia with silicate transported from the Southern Ocean. The strong decrease of the siliceous signal throughout MIS 2 represents a decrease in the nutrient input to the BUS, even though the diatom assemblage is still dominated by spores of the upwelling-associated diatom genus Chaetoceros. Depletion of silicate in the thermocline from the onset of MIS 2 through to the early Holocene reflects the shutdown of AAIW injection from the Southern Ocean into the BUS, causing upwelled waters to become reduced in silicate, hence less favourable for diatom production. The deglaciation and early Holocene are characterised by the replacement of the upwelling-associated flora by a non-upwelling-related diatom community, reflecting weakened upwelling, retraction of the seaward extension of the chlorophyll filament off Lüderitz, and dominance of warmer waters. Other/Unknown Material Antarc* Antarctic Southern Ocean PANGAEA - Data Publisher for Earth & Environmental Science ENVELOPE(13.083333,13.083333,-25.466667,-25.466667) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
Center for Marine Environmental Sciences GeoB GeoB3606-1 Geosciences University of Bremen Gravity corer (Kiel type) M34/1 MARUM Meteor (1986) Northern Cape Basin SL |
spellingShingle |
Center for Marine Environmental Sciences GeoB GeoB3606-1 Geosciences University of Bremen Gravity corer (Kiel type) M34/1 MARUM Meteor (1986) Northern Cape Basin SL Romero, Oscar E Mollenhauer, Gesine Schneider, Ralph R Wefer, Gerold High resolution study of sediment core GeoB3606-1 |
topic_facet |
Center for Marine Environmental Sciences GeoB GeoB3606-1 Geosciences University of Bremen Gravity corer (Kiel type) M34/1 MARUM Meteor (1986) Northern Cape Basin SL |
description |
Based on a high-resolution analysis of the diatom signal and biogenic bulk components at site GeoB3606-1 (25°S, off Namibia), we describe rapid palaeoceanographic changes in the Benguela Upwelling System (BUS) from early MIS 3 through to the early Holocene (55 000 to 7 000 14C yr BP). Coastal upwelling strongly varied at 25°S from MIS 3 through to MIS 2. The abrupt decrease in the accumulation rate of biogenic silica and diatoms from MIS 3 into MIS 2 records rapid oceanographic changes in the BUS off Namibia. During MIS 3, leakage of excess H4SiO4 acid from the Southern Ocean into low-latitude surface waters, as indicated by the occurrence of Antarctic diatoms, enhanced the production of spores of Chaetoceros at the expense of calcareous phytoplankton. Furthermore, shallower Antarctic Intermediate Water (AAIW) would have enriched the thermocline off Namibia with silicate transported from the Southern Ocean. The strong decrease of the siliceous signal throughout MIS 2 represents a decrease in the nutrient input to the BUS, even though the diatom assemblage is still dominated by spores of the upwelling-associated diatom genus Chaetoceros. Depletion of silicate in the thermocline from the onset of MIS 2 through to the early Holocene reflects the shutdown of AAIW injection from the Southern Ocean into the BUS, causing upwelled waters to become reduced in silicate, hence less favourable for diatom production. The deglaciation and early Holocene are characterised by the replacement of the upwelling-associated flora by a non-upwelling-related diatom community, reflecting weakened upwelling, retraction of the seaward extension of the chlorophyll filament off Lüderitz, and dominance of warmer waters. |
format |
Other/Unknown Material |
author |
Romero, Oscar E Mollenhauer, Gesine Schneider, Ralph R Wefer, Gerold |
author_facet |
Romero, Oscar E Mollenhauer, Gesine Schneider, Ralph R Wefer, Gerold |
author_sort |
Romero, Oscar E |
title |
High resolution study of sediment core GeoB3606-1 |
title_short |
High resolution study of sediment core GeoB3606-1 |
title_full |
High resolution study of sediment core GeoB3606-1 |
title_fullStr |
High resolution study of sediment core GeoB3606-1 |
title_full_unstemmed |
High resolution study of sediment core GeoB3606-1 |
title_sort |
high resolution study of sediment core geob3606-1 |
publisher |
PANGAEA |
publishDate |
2003 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.779190 https://doi.org/10.1594/PANGAEA.779190 |
op_coverage |
LATITUDE: -25.466667 * LONGITUDE: 13.083333 * DATE/TIME START: 1996-01-15T00:00:00 * DATE/TIME END: 1996-01-15T00:00:00 |
long_lat |
ENVELOPE(13.083333,13.083333,-25.466667,-25.466667) |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_source |
Supplement to: Romero, Oscar E; Mollenhauer, Gesine; Schneider, Ralph R; Wefer, Gerold (2003): Oscillations of the siliceous imprint in the central Benguela Upwelling System from MIS3 through the early Holocene: the influence of the Southern Ocean. Journal of Quaternary Science, 18(8), 733-743, https://doi.org/10.1002/jqs.789 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.779190 https://doi.org/10.1594/PANGAEA.779190 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1594/PANGAEA.77919010.1002/jqs.789 |
_version_ |
1810288793658327040 |