Surface sediment data, CaCO3 and TOC
Fuente:
PANGAEA
Gespeichert in:
| Hauptverfasser: | , , , , |
|---|---|
| Format: | Dataset Open Access |
| Sprache: | en |
| Veröffentlicht: |
PANGAEA
2002
|
| Schlagworte: | |
| Online-Zugang: | |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| _version_ | 1867170488944427008 |
|---|---|
| author | Mollenhauer, Gesine Schneider, Ralph R Müller, Peter J Spieß, Volkhard Wefer, Gerold |
| author_facet | Mollenhauer, Gesine Schneider, Ralph R Müller, Peter J Spieß, Volkhard Wefer, Gerold |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | Modern sedimentary total organic carbon (TOC) content as a proxy for surface water export production was mapped on the shelf and on the upper continental slope of the Benguela upwelling system using 137 core tops. Shelf maxima in TOC can be correlated with maxima in surface water productivity. On the slope, high TOC contents are observed offshore from sites of strong modern upwelling. Estimates of modern TOC mass accumulation rates (MAR) show that approximately 85% of the total is accumulating on the shelf. TOC MAR were calculated, mapped, and budgeted for the Holocene and for the Last Glacial Maximum (LGM) using 19 sediment cores from the continental slope. During the LGM, centers of deposition and production have migrated offshore with respect to their Holocene positions. TOC accumulation on the continental slope was approximately 84% higher during the LGM than during the Holocene, possibly reflecting enhanced productivity. The TOC distribution patterns and sediment echo sounding data suggest that undercurrents strongly influence the sedimentation off Namibia. Winnowing and focusing result in great lateral heterogeneity of sedimentation rates and sediment properties. Individual cores therefore do not necessarily reflect general changes in export production. These results highlight the need for detailed regional studies based on a large number of sediment cores for highly heterogeneous high-productivity areas in order to derive general statements on total fluxes. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_59873 |
| institution | PANGAEA |
| language | en |
| publishDate | 2002 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Surface sediment data, CaCO3 and TOC Mollenhauer, Gesine Schneider, Ralph R Müller, Peter J Spieß, Volkhard Wefer, Gerold Angola Benguela Front; Calcium carbonate; Carbon, organic, total; Date/Time of event; DEPTH, sediment/rock; Element analyser CHN; Elevation of event; Event label; GeoB; GeoB2310-1; GeoB3606-2; GeoB3607-1; GeoB3608-1; GeoB3701-1; GeoB3702-2; GeoB3703-4; GeoB3704-2; GeoB3705-2; GeoB3706-3; GeoB3707-3; GeoB3708-1; GeoB3709-1; GeoB3710-1; GeoB3711-1; GeoB3715-1; GeoB3717-1; GeoB3718-4; GeoB3719-2; GeoB3720-1; GeoB3721-4; GeoB3722-1; GeoB3723-2; GeoB3724-1; GeoB3725-1; Geosciences, University of Bremen; Latitude of event; Longitude of event; M34/1; M34/2; Meteor (1986); MUC; MultiCorer; Northern Cape Basin; PROBOSWA; SFB261; SO86; Sonne; South Atlantic in Late Quaternary: Reconstruction of Budget and Currents Modern sedimentary total organic carbon (TOC) content as a proxy for surface water export production was mapped on the shelf and on the upper continental slope of the Benguela upwelling system using 137 core tops. Shelf maxima in TOC can be correlated with maxima in surface water productivity. On the slope, high TOC contents are observed offshore from sites of strong modern upwelling. Estimates of modern TOC mass accumulation rates (MAR) show that approximately 85% of the total is accumulating on the shelf. TOC MAR were calculated, mapped, and budgeted for the Holocene and for the Last Glacial Maximum (LGM) using 19 sediment cores from the continental slope. During the LGM, centers of deposition and production have migrated offshore with respect to their Holocene positions. TOC accumulation on the continental slope was approximately 84% higher during the LGM than during the Holocene, possibly reflecting enhanced productivity. The TOC distribution patterns and sediment echo sounding data suggest that undercurrents strongly influence the sedimentation off Namibia. Winnowing and focusing result in great lateral heterogeneity of sedimentation rates and sediment properties. Individual cores therefore do not necessarily reflect general changes in export production. These results highlight the need for detailed regional studies based on a large number of sediment cores for highly heterogeneous high-productivity areas in order to derive general statements on total fluxes. |
| title | Surface sediment data, CaCO3 and TOC |
| topic | Angola Benguela Front; Calcium carbonate; Carbon, organic, total; Date/Time of event; DEPTH, sediment/rock; Element analyser CHN; Elevation of event; Event label; GeoB; GeoB2310-1; GeoB3606-2; GeoB3607-1; GeoB3608-1; GeoB3701-1; GeoB3702-2; GeoB3703-4; GeoB3704-2; GeoB3705-2; GeoB3706-3; GeoB3707-3; GeoB3708-1; GeoB3709-1; GeoB3710-1; GeoB3711-1; GeoB3715-1; GeoB3717-1; GeoB3718-4; GeoB3719-2; GeoB3720-1; GeoB3721-4; GeoB3722-1; GeoB3723-2; GeoB3724-1; GeoB3725-1; Geosciences, University of Bremen; Latitude of event; Longitude of event; M34/1; M34/2; Meteor (1986); MUC; MultiCorer; Northern Cape Basin; PROBOSWA; SFB261; SO86; Sonne; South Atlantic in Late Quaternary: Reconstruction of Budget and Currents |
| url | https://doi.org/10.1594/PANGAEA.59873 |