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| Nurnberg, D; Tiedemann, R. |
| On the basis of two sedimentary records from the central Sea of Okhotsk, we reconstruct the closely coupled glacial/interglacial changes in terrigenous flux, marine productivity, and sea ice coverage over the past 1.1 Myr. The correspondance of our sedimentary records to the China loess grain size record ( China loess particle timescale, CHILOPARTS) suggests that environmental changes in both the Sea of Okhotsk area and in SE Asia were closely related via the Siberian atmospheric high-pressure cell. During full glacial times our records point to a strong Siberian High causing northerly wind directions, the extension of the sea ice cover, and a reduced Amur River discharge. Deglacial maxima of terrigenous flux were succeeded by or synchronous to... |
| Tipo: Text |
Palavras-chave: Sea of Okhotsk; Paleoproductivity; Terrigenous flux; Sea ice dynamics; Stratigraphy. |
| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/00228/33934/32231.pdf |
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| Aracena, Claudia; Kilian, Rolf; Lange, Carina B.; Bertrand, Sebastien; Lamy, Frank; Arz, Helge W.; De Pol-holz, Ricardo; Baeza, Oscar; Pantoja, Silvio; Kissel, Catherine. |
| One of the most important factors controlling fjord primary production in southernmost Patagonia is the variability in the thermohaline structure of the water column. In the present-day environment, thermal stratification is mostly related to freshwater input and in particular, the seasonal melting of glaciers. Here we assess whether this relation between fjord productivity and freshwater input holds true for the Holocene, using a sediment record from the central basin of the Strait of Magellan (core MD07-3132, 53°44.17′S; 70°19.03′W, 301 m). Our approach relies on a proxy-based reconstruction of fjord sea surface temperature (alkenone SST), paleosalinity, freshwater input, and paleoproductivity. The results indicate that, during the early Holocene, the... |
| Tipo: Text |
Palavras-chave: Strait of Magellan; Holocene; Paleoproductivity; Thermohaline conditions. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00294/40518/39325.pdf |
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| Amore, F. O.; Flores, J. A.; Voelker, A. H. L.; Lebreiro, S. M.; Palumbo, E.; Sierro, F. J.. |
| Changes in paleoclimate and paleoproductivity patterns have been identified by analysing, in conjunction with other available proxy data, the coccolithophore assemblages from core MD03-2699, located in the Portuguese margin in the time interval from the Marine Isotope Stage (MIS) 13/14 boundary to MIS 9 (535 to 300 ka). During the Mid-Brunhes event, the assemblages associated with the eccentricity minima are characterised by higher nannoplankton accumulation rate (NAR) values and by the blooming of the opportunistic genus Gephyrocapsa. Changes in coccolithophore abundance are also related to glacial-interglacial cycles. Higher NAR and numbers of coccoliths/g mainly occurred during the interglacial periods, while these values decreased during the glacial... |
| Tipo: Text |
Palavras-chave: North Atlantic Ocean; Mid-Pleistocene; Coccolithophores; Paleoclimate; Paleoproductivity. |
| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00092/20286/17946.pdf |
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| Ríos, Francisco; Kilian, Rolf; Lange, Carina B.; Baeza-urrea, Oscar; Arz, Helge W.; Zindorf, Mark; De Pol-holz, Ricardo; Lamy, Frank. |
| Organic-rich sediments of the southernmost Chilean Pacific coast and its fjord system constitute an important component of the global marine carbon budget. Sediment records from Trampa and Caribe bays and Churruca fjord in the western Magellan fjord system have been analyzed with the goal of understanding the factors controlling carbon accumulation and its regional fluctuation throughout the Holocene. The individual response in paleoproductivity at the different sites and related variations in accumulation rates document a very complex interplay among local and regional-scale environmental changes, and coastline elevation across the Holocene. Shallow sill basins close to the Pacific coast, as the ones studied here, are particularly sensitive to these... |
| Tipo: Text |
Palavras-chave: Patagonian fjord sediments; Paleoproductivity; Carbon accumulation; Biogenic carbonate; Marine transgression; Holocene. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00614/72576/71536.pdf |
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