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Sunniva Rutledal Haflidi Haflidason Sarah M. P. Berben Lisa Griem Eystein Jansen 《第四纪科学杂志》2020,35(7):855-868
Volcanic ash preserved in marine sediment sequences is key for independent synchronization of palaeoclimate records within and across different climate archives. Here we present a continuous tephrostratigraphic record from the Labrador Sea, spanning the last 65–5 ka, an area and time period that has not been investigated in detail within the established North Atlantic tephra framework. We investigated marine sediment core GS16-204-22CC for increased tephra occurrences and geochemically analysed the major element composition of tephra shards to identify their source volcano(es). In total we observed eight tephra zones, of which five concentration peaks show isochronous features that can be used as independent tie-points in future studies. The main transport mechanism of tephra shards to the site was near-instantaneous deposition by drifting of sea ice along the East Greenland Current. Our results show that the Icelandic Veidivötn volcanic system was the dominant source of tephra material, especially between late Marine Isotope Stage (MIS) 4 and early MIS 3. The Veidivötn system generated volcanic eruptions in cycles of ca. 3–5 ka. We speculate that the quantity of tephra delivered to the Labrador Sea was a result of variable Icelandic ice volume and/or changes in the transportation pathway towards the Labrador Sea. 相似文献
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The effect of the water soluble oil dispersant Corexit 9527 was tested on larvae from several species of sea urchins and marine fishes. Severe effects in fertilization and development were registered often resulting in pathological larvae and rapid cytolysis. The combination of Corexit 9527 with oil was found to be even more dangerous to the embryo than Corexit or oil alone. 相似文献
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Leiv K. Sydnes Ivan C. Burkow Anne Stene Sunniva Lønning 《Marine environmental research》1985,16(2):115-126
The toxicity of various oil extracts has been studied using cod eggs as test organisms. The most toxic effect was observed when the eggs were kept underneath the water/oil interface during irradiation. This supports the notion that toxic primary photoproducts with a short life-time are generated when oil on seawater is illuminated. 相似文献
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The effect of a plastic oil absorbant was tested on several different test organisms of different taxonomic positions. The results indicate that the Oil Killer under the experimental conditions described, acts as an almost inert nontoxic substance. The Oil Killer dissolves in the presence of methylene chloride but in spite of this no negative effects were recorded. In combination with crude oil the Oil Killer seems rather to reduce the serious ill effects exerted by oil alone. 相似文献
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The water-soluble oil dispersant Esso Corexit 9527 has earlier been found to interfere, even in low concentrations, with fertilization and development. Further studies of the effect on sea urchin spermatozoa demonstrate that Corexit 9527 gives negative biological effects in concentrations down to 0.0003 ppm. 相似文献
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