Recent biogenic sedimentation on the Antarctic continental margin
Floral and geochemical analyses were conducted on sinking and suspended particulate matter, and on sea ice and recent sediment samples from the northwestern Weddell Sea--northern Antarctic Peninsula area, and McMurdo Sound, in the southwestern Ross Sea. Data from McMurdo Sound reveal that although l...
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ftriceuniv:oai:scholarship.rice.edu:1911/16161 2023-05-15T13:39:43+02:00 Recent biogenic sedimentation on the Antarctic continental margin Leventer, Amy Ruth Dunbar, Robert B. 1988 249 p. application/pdf https://hdl.handle.net/1911/16161 eng eng Leventer, Amy Ruth. "Recent biogenic sedimentation on the Antarctic continental margin." (1988) Diss., Rice University. https://hdl.handle.net/1911/16161 . https://hdl.handle.net/1911/16161 Thesis Geol. 1988 Leventer Geology Paleontology Thesis Text 1988 ftriceuniv 2022-08-09T20:30:31Z Floral and geochemical analyses were conducted on sinking and suspended particulate matter, and on sea ice and recent sediment samples from the northwestern Weddell Sea--northern Antarctic Peninsula area, and McMurdo Sound, in the southwestern Ross Sea. Data from McMurdo Sound reveal that although large numbers of diatom frustules dissolve within the upper water column the decrease in silica mass flux is much smaller. At mid-water depths, increases in the absolute flux of Nitzschia curta and Thalassiosira spp. indicate the influence of lateral advection. Within a near-bottom nepheloid layer additional dissolution occurs. Dilution and preferential dissolution is responsible for production of a surface sediment assemblage dominated by Thalassiosira spp. and Nitzschia curta. The surface sediment diatom assemblage in McMurdo Sound documents the seasonal history of sea ice extent and regional circulation patterns. Thalassiosira spp., indicative of water column primary productivity, is most common in eastern and northwestern McMurdo Sound, the result of advection from areas of open water. Nitzschia curta, a member of the sea ice microbial community and of ice edge blooms in the Ross Sea is most abundant in the southwestern Sound where the northward advection of oligotrophic water results in the dominance of the local flora. Maximum downcore Thalassiosira abundances occurred between 1600-1875 A.D., during the Little Ice Age. Warmer atmospheric temperatures or more persistent winds may have been responsible for more prevalent polynyas, suggesting that within the southwestern Ross Sea, the production of High Salinity Shelf Water, and hence Antarctic Bottom Water, may have been greater at that time. Measurements of water and acid soluble and insoluble phosphate performed on samples of suspended particulate matter from the Antarctic Peninsula region show the concentration of water-soluble, loosely bound organic phosphates decreases rapidly within the upper 100 m, the result of rapid phosphorus regeneration. A gradual ... Thesis Antarc* Antarctic Antarctic Peninsula McMurdo Sound Ross Sea Sea ice Weddell Sea Rice University: Digital Scholarship Archive Antarctic Antarctic Peninsula McMurdo Sound Ross Sea The Antarctic Weddell Weddell Sea |
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Rice University: Digital Scholarship Archive |
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ftriceuniv |
language |
English |
topic |
Geology Paleontology |
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Geology Paleontology Leventer, Amy Ruth Recent biogenic sedimentation on the Antarctic continental margin |
topic_facet |
Geology Paleontology |
description |
Floral and geochemical analyses were conducted on sinking and suspended particulate matter, and on sea ice and recent sediment samples from the northwestern Weddell Sea--northern Antarctic Peninsula area, and McMurdo Sound, in the southwestern Ross Sea. Data from McMurdo Sound reveal that although large numbers of diatom frustules dissolve within the upper water column the decrease in silica mass flux is much smaller. At mid-water depths, increases in the absolute flux of Nitzschia curta and Thalassiosira spp. indicate the influence of lateral advection. Within a near-bottom nepheloid layer additional dissolution occurs. Dilution and preferential dissolution is responsible for production of a surface sediment assemblage dominated by Thalassiosira spp. and Nitzschia curta. The surface sediment diatom assemblage in McMurdo Sound documents the seasonal history of sea ice extent and regional circulation patterns. Thalassiosira spp., indicative of water column primary productivity, is most common in eastern and northwestern McMurdo Sound, the result of advection from areas of open water. Nitzschia curta, a member of the sea ice microbial community and of ice edge blooms in the Ross Sea is most abundant in the southwestern Sound where the northward advection of oligotrophic water results in the dominance of the local flora. Maximum downcore Thalassiosira abundances occurred between 1600-1875 A.D., during the Little Ice Age. Warmer atmospheric temperatures or more persistent winds may have been responsible for more prevalent polynyas, suggesting that within the southwestern Ross Sea, the production of High Salinity Shelf Water, and hence Antarctic Bottom Water, may have been greater at that time. Measurements of water and acid soluble and insoluble phosphate performed on samples of suspended particulate matter from the Antarctic Peninsula region show the concentration of water-soluble, loosely bound organic phosphates decreases rapidly within the upper 100 m, the result of rapid phosphorus regeneration. A gradual ... |
author2 |
Dunbar, Robert B. |
format |
Thesis |
author |
Leventer, Amy Ruth |
author_facet |
Leventer, Amy Ruth |
author_sort |
Leventer, Amy Ruth |
title |
Recent biogenic sedimentation on the Antarctic continental margin |
title_short |
Recent biogenic sedimentation on the Antarctic continental margin |
title_full |
Recent biogenic sedimentation on the Antarctic continental margin |
title_fullStr |
Recent biogenic sedimentation on the Antarctic continental margin |
title_full_unstemmed |
Recent biogenic sedimentation on the Antarctic continental margin |
title_sort |
recent biogenic sedimentation on the antarctic continental margin |
publishDate |
1988 |
url |
https://hdl.handle.net/1911/16161 |
geographic |
Antarctic Antarctic Peninsula McMurdo Sound Ross Sea The Antarctic Weddell Weddell Sea |
geographic_facet |
Antarctic Antarctic Peninsula McMurdo Sound Ross Sea The Antarctic Weddell Weddell Sea |
genre |
Antarc* Antarctic Antarctic Peninsula McMurdo Sound Ross Sea Sea ice Weddell Sea |
genre_facet |
Antarc* Antarctic Antarctic Peninsula McMurdo Sound Ross Sea Sea ice Weddell Sea |
op_relation |
Leventer, Amy Ruth. "Recent biogenic sedimentation on the Antarctic continental margin." (1988) Diss., Rice University. https://hdl.handle.net/1911/16161 . https://hdl.handle.net/1911/16161 Thesis Geol. 1988 Leventer |
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1766122532411277312 |