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Carbonate budget of a cold-water coral carbonate mound: Propeller Mound,Porcupine Seabight 总被引：1，自引：0，他引：1
Boris Dorschel Dierk Hebbeln Andres Rüggeberg Christian Dullo 《International Journal of Earth Sciences》2007,96(1):73-83
High resolution studies from the Propeller Mound, a cold-water coral carbonate mound in the NE Atlantic, show that this mound
consists of >50% carbonate justifying the name ‘carbonate mound’. Through the last ~300,000 years approximately one third
of the carbonate has been contributed by cold-water corals, namely Lophelia pertusa and Madrepora oculata. This coral bound contribution to the carbonate budget of Propeller Mound is probably accompanied by an unknown portion of
sediments buffered from suspension by the corals. However, extended hiatuses in Propeller Mound sequences only allow the calculation
of a net carbonate accumulation. Thus, net carbonate accumulation for the last 175 kyr accounts for only <0.3 g/cm2/kyr, which is even less than for the off-mound sediments. These data imply that Propeller Mound faces burial by hemipelagic
sediments as has happened to numerous buried carbonate mounds found slightly to the north of the investigated area. 相似文献
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International Journal of Earth Sciences - The Eschers, an old Swiss family which for many generations were members of the Council of Zurich, were dedicated to technical and economic development.... 相似文献
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The volcano Cotopaxi in South America is 5,897 m high and is one of the highest active volcanoes of the world and the second highest volcano in the Andes after the Chimborazo (6,310 m). In Ecuador, there are more than 20 volcanoes contributing to the spectacular mountain range diving this country between the western and eastern lowlands. There have been more than 50 reports of volcanic activity at Cotopaxi since 1738, among which those from the years 1744, 1768, and 1877 are the largest. During the 1877 eruption, the whole summit glacier collapsed and a huge mudflow spread out for more than 100 km and flooded the city of Latacunga. Five years prior to this catastrophic event, the German geologist Wilhelm Reiss from the University of Heidelberg ascended Cotopaxi for the first time together with his supporter Angel M. Escobar from Columbia. 相似文献
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Sri Yudawati Cahyarini Miriam Pfeiffer W.-Chr. Dullo 《International Journal of Earth Sciences》2009,98(1):31-40
We reconstruct SST from coral Sr/Ca ratios measured at three coral cores taken from the lagoon of Tahiti (French Polynesia).
Two coral cores were drilled from the same coral colony (one horizontally and one vertically), and a third core was drilled
vertically from another coral growing at a different site. We evaluate several Sr/Ca records as proxies for regional SST variations:
(1) the three single-core records from Tahiti, (2) an average Sr/Ca record computed from the two cores drilled from the same
coral colony, (3) an average Sr/Ca record computed from all three Tahiti cores, and (4) an average Sr/Ca record computed from
the three Tahiti cores and a fourth core taken from a different island (Rarotonga). On a monthly scale, the average Sr/Ca
record including the four coral cores from Tahiti and Rarotonga shows the best correlation with regional SST. The variance
of the SST reconstruction is very realistic and the residual SST is low. This suggests that reconstructing SST from average
proxy records gives a better representation of regional SST variations. Of the three Tahiti cores, the one that was drilled
horizontally shows the best correlation with grid-SST on an annual mean scale. All three Tahiti corals show much larger interannual
SST variations than that indicated by grid-SST. 相似文献
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Michel Colonna Joel Casanova Wolf-Christian Dullo Gilbert Camoin 《Quaternary Research》1996,46(3):335-339
New sea-level and δ18O curves for the past 34,000 yr, based on uranium–thorium chronology, are proposed for the southwestern part of the Indian Ocean. The archives include cores drilled from onshore coral reefs and submersed samples from foreslope corals of Mayotte in the Comoro Islands. The Mayotte sea-level curve shows a lowstand of 145 ± 5 m below the present level during the last glacial maximum dated at 18,400 yr. This lowstand is supported by the maximum18O enrichment in the coral colonies. The residual signal (Δδ18O), controlled by sea-surface temperature changes, indicates that surface waters 18,400 yr ago were approximately 5°C cooler than present. The deglacial sea-level rise is clearly recorded, with a mean rate of about 1.7 cm yr−1between 18,400 and 10,000 yr ago. The deglaciation phase is characterized by a strong18O depletion marked by two pulses related to meltwater discharges into the North Atlantic Ocean but also characterized by responses specific to the tropical Indian Ocean. 相似文献
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A study of surface sediment organic matter and heavy metal content (e.g. Cu, Zn, Pb and Sn) was carried out in 2006 to assess changes in eutrophication and pollution in the periodically anoxic Flensburg Fjord since 1972. Low hydrodynamic activity together with sewage discharges and high primary production in the inner fjord promote the enrichment of present day surface sediments in organic matter and metals in contrast to the outer fjord. However, heavy metal contents in the fjord are typical for the western Baltic Sea, although they are higher than in the preindustrial period.Although the anthropogenic nutrient load has substantially decreased since the 1970s, sediments from the inner fjord contain more organic material in 2006 than in 1972 resulting from still high levels of primary production supported by internal nutrient loading. Of the heavy metals measured, a decrease in Pb content since the 1970s is distinct, which is explained by the banning on gasoline lead. Taken together, these results suggest that the amelioration of environmental conditions needs time but is indeed related to reduced anthropogenic inputs. 相似文献
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Wolfgang Schott is the pioneer in paleoceanography and has established this research field within marine geology. His papers from the first half of the twentieth century are all published in German; therefore, the most inspiring results are given here as original quotes in English, since they paved the ground for all scientific discussions on climate stratigraphy, past ocean currents, and glacial interglacial cycles. 相似文献