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| Jaeschke, Andrea; Ziegler, Martin; Hopmans, Ellen C.; Reichart, Gert-jan; Lourens, Lucas J.; Schouten, Stefan; Damste, Jaap S. Sinninghe. |
| Anaerobic ammonium oxidation (anammox) has been recognized as an important process converting fixed nitrogen to N(2) in many marine environments, thereby having a major impact on the present-day marine nitrogen cycle. However, essentially nothing is known about the importance of anammox in past marine nitrogen cycles. In this study, we analyzed the distribution of fossil ladderane lipids, derived from bacteria performing anammox, in a sediment core from the northern Arabian Sea. Concentrations of ladderane lipids varied between 0.3 and 5.3 ng g(-1) sediment during the past 140 ka, with high values observed during the Holocene, intervals during the last glacial, and during the penultimate interglacial. Maxima in ladderane lipid abundances correlate with... |
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| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00218/32942/31436.pdf |
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| Ziegler, Martin; Lourens, Lucas J.; Tuenter, Erik; Hilgen, Frits; Reichart, Gert-jan; Weber, Nanne. |
| Results from transient climate modeling experiments indicate an in-phase relationship between insolation forcing and Indian summer monsoonal precipitation. This is in contrast to high-resolution radioisotopically dated speleothem oxygen isotope (delta O-18) records of China, which showed that East Asian Monsoon maxima lag Northern Hemisphere peak summer insolation by similar to 2,700 years, while an approximately 8,000-year time lag was derived from late Pleistocene records of Arabian Sea sediments. Here, we evaluate the precession phase of the Arabian Sea signal by comparing a new high-resolution productivity and oxygen minimum zone (OMZ) intensity record from the Arabian Sea over the past 450,000 years with the results of a transient climate modeling... |
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| Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00231/34177/32908.pdf |
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| Koho, Karoliina A.; De Nooijer, Lennart J.; Fontanier, Christophe; Toyofuku, Takashi; Oguri, Kazumasa; Kitazato, Hiroshi; Reichart, Gert-jan. |
| The Mn / Ca of calcium carbonate tests of living (rose-Bengal-stained) benthic foraminifera (Elphidium batialis, Uvigerina spp., Bolivina spissa, Nonionellina labradorica and Chilostomellina fimbriata) were determined in relation to pore water manganese (Mn) concentrations for the first time along a bottom water oxygen gradient across the continental slope along the NE Japan margin (western Pacific). The local bottom water oxygen (BWO) gradient differs from previous field study sites focusing on foraminiferal Mn / Ca and redox chemistry, therefore allowing further resolution of previously observed trends. The Mn / Ca ratios were analysed using laser ablation inductively coupled plasma-mass spectrometer (ICP-MS), allowing single-chamber determination of Mn... |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00391/50237/50880.pdf |
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| Toyofuku, Takashi; Duros, Pauline; Fontanier, Christophe; Mamo, Briony; Bichon, Sabrina; Buscail, Roselyne; Chabaud, Gerard; Deflandre, Bruno; Goubet, Sarah; Gremare, Antoine; Menniti, Christophe; Fujii, Minami; Kawamura, Kiichiro; Koho, Karoliina Annika; Noda, Atsushi; Namegaya, Yuichi; Oguri, Kazumasa; Radakovitch, Olivier; Murayama, Masafumi; De Nooijer, Lennart Jan; Kurasawa, Atushi; Ohkawara, Nina; Okutani, Takashi; Sakaguchi, Arito; Jorissen, Frans; Reichart, Gert-jan; Kitazato, Hiroshi. |
| On March 11th, 2011 the Mw 9.0 2011 Tohoku-Oki earthquake resulted in a tsunami which caused major devastation in coastal areas. Along the Japanese NE coast, tsunami waves reached maximum run-ups of 40 m, and travelled kilometers inland. Whereas devastation was clearly visible on land, underwater impact is much more difficult to assess. Here, we report unexpected results obtained during a research cruise targeting the seafloor off Shimokita (NE Japan), shortly (five months) after the disaster. The geography of the studied area is characterized by smooth coastline and a gradually descending shelf slope. Although high-energy tsunami waves caused major sediment reworking in shallow-water environments, investigated shelf ecosystems were characterized by... |
| Tipo: Text |
Palavras-chave: Palaeoceanography; Biodiversity. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00248/35914/34453.pdf |
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