Untersuchungen zum regionalen Verteilungsmuster benthischer Stoffflüsse unter Berücksichtigung biogeographischer Provinzen im Arabischen Meer und im Atlantik
The overall research topic of this thesis was to investigate early-diagenetic remineralization processes in marine surface sediments, thus focussing on diffusive transport processes at the sediment-water interface. The amount and the distribution pattems of benthic nutrient fluxes were investigated...
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| Format: | Thesis |
| Language: | German |
| Published: |
2000
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| Online Access: | https://oceanrep.geomar.de/id/eprint/48016/ https://oceanrep.geomar.de/id/eprint/48016/1/Grandle.pdf |
| Summary: | The overall research topic of this thesis was to investigate early-diagenetic remineralization processes in marine surface sediments, thus focussing on diffusive transport processes at the sediment-water interface. The amount and the distribution pattems of benthic nutrient fluxes were investigated to emphasize regional differences in the coupling and relationship of primary production at the surface and remineralization at the seafloor. Field examinations were executed in abyssal regions of the Arabian Sea and the Northeast Atlantic. In addition, the distribution pattems of primary production, benthic nitrate and silicic acid fluxes were investigated using published data sets. These regional considerations were based on a division of the ocean into biogeographical provinces after LONGHURST (1995; 1998) which are based on regional oceanographic and ecologic characteristics of the upper water column. The benthic investigations executed in abyssal regions of the Arabian Sea represent a main contribution to understand early diagenetic remineralization processes in this part of the ocean. The benthic nutrient fluxes reveal a distinct regional distribution pattern, with high benthic fluxes in the range of 106 mmol NO3 - *m-2*yr1 and 300 mmol H4SiO4 *m-2*yr-1, respectively, in the northwestern part and two to three times decreasing fluxes towards the southeastern part. The high fluxes found in the northwestern Arabian Sea are in the range of Si-fluxes measured in the southern South Atlantic. They correspond furthermore with dominating diatoms in the phytoplankton community in the northwestern Arabian Sea. Thus the benthic nitrate and silicic acid fluxes reflect the distribution pattems of the primary production induced by the monsoonal regime. Investigations regarding a temporal variability of benthic fluxes revealed no significant differences between the two intermonsoon periods with exception of the station WAST. The non-steady-state conditions, just examined at WAST are considered to be not only due to a varying ... |
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