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| BRUUN, S.; EL-ZEHERY, T.. |
| The objective of this work was to verify whether the addition of biochar to the soil affects the degradation of litter and of soil organic matter (SOM). In order to investigate the effect of biochar on the mineralization of barley straw, soil was incubated with 14C-labelled barley straw with or without unlabelled biochar. To investigate the effect of straw on the mineralization of biochar, soil was incubated with 14C-labelled biochar with or without straw. In addition, to investigate the effect of biochar on old SOM, a soil labelled by applying labelled straw 40 years ago was incubated with different levels of biochar. All experiments had a control treatment, without any soil amendment. The effect of biochar on the straw mineralization was small and... |
| Tipo: Artigo em periódico indexado (ALICE) |
Palavras-chave: Anthropogenic dark earth; Organic matter stability; Priming effect; Radiocarbon. |
| Ano: 2012 |
URL: http://www.alice.cnptia.embrapa.br/handle/doc/930311 |
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| Soulet, Guillaume; Menot, Guillemette; Garreta, Vincent; Rostek, Frauke; Zaragosi, Sebastien; Lericolais, Gilles; Bard, Edouard. |
| Chronologies of sediments that document the last glacial history of the Black Sea "Lake" are hampered by issues relating to reservoir age. Regulated by basin hydrology, reservoir ages represent a tool that could potentially be used to better understand the response of Black Sea "Lake" hydrology to climate change. Therefore, deciphering reservoir age evolution is crucial both for better constraining the basin chronological framework and for providing new insights into our understanding of Black Sea "Lake" hydrology. By tuning a meaningful new high-resolution geochemical dataset (obtained from core MD04-2790) to a climate reference record, here, we propose a reliable chronology spanning the last 32 kyr BP. The chronology is compared to a large AMS... |
| Tipo: Text |
Palavras-chave: Black Sea; Reservoir age; Radiocarbon; Last Glacial; Last Deglaciation; Paleoclimate. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00043/15379/12817.pdf |
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| Blamer, Sven. |
| The 14C reservoir age of ocean surface waters shows small-scale spatial and temporal variations. Accordingly, correct estimates of reservoir ages are crucial for any reconstruction of a precise radiocarbon-based chronology of marine sediments. To meet this target in the mid- and low- latitude Atlantic we obtained both 14C reservoir ages and an absolute age model for the glacial-to-deglacial sections of four marine sediment cores by means of the ‘14C Plateau Tuning Technique’. This method is independent of any common conversion scheme of 14C ages. The resulting empiric reservoir ages were compared with reservoir age estimates based on model simulations. |
| Tipo: Text |
Palavras-chave: Reservoir ages; Deep water ventilation ages; Atlantic; Radiocarbon. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00493/60445/63890.pdf |
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| Lindsay, Colin M.; Lehman, Scott J.; Marchitto, Thomas M.; Carriquiry, Jose D.; Ortiz, Joseph D.. |
| Previous studies have shown that radiocarbon activities (C-14) in the low-latitude, middepth Pacific and Indian Oceans were anomalously low during Heinrich Stadial 1 (HS1, similar to 17.8-14.6ka) and the Younger Dryas (YD, similar to 12.8-11.5ka), coincident with intervals of rising atmospheric CO2 concentration and declining atmospheric C-14. However, a full explanation of these events remains elusive due to sparse and sometimes conflicting data. Here we present new C-14 measurements on benthic and planktic foraminifera that, in combination with previously published measurements, enable us to reconstruct the C-14 depth gradient near Baja California. Vertical profiles were similar to present during the Last Glacial Maximum and BOlling/Allerod (14.6-12.8ka)... |
| Tipo: Text |
Palavras-chave: Radiocarbon; Deglaciation; Heinrich Stadial 1; Baja California; Benthic foraminifera. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00496/60797/64925.pdf |
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| Ronge, Thomas A.; Prange, M.; Mollenhauer, Gesine; Ellinghausen, Maret; Kuhn, G.; Tiedemann, R.. |
| It is widely assumed that the ventilation of the Southern Ocean played a crucial role in driving glacial‐interglacial atmospheric CO2‐levels. So far however, ventilation records from the Indian sector of the Southern Ocean, are widely missing. Here we present reconstructions of water residence times (depicted as ΔΔ14C and Δδ13C) for the last 32,000 years on sediment records from the Kerguelen Plateau and the Conrad Rise (~570‐2500 m water depth), along with simulated changes in ocean stratification from a transient climate model experiment. Our data indicate that Circumpolar Deep Waters in the Indian Ocean were part of the glacial carbon pool. At our sites, close to or bathed by upwelling deep‐waters, we find two pulses of decreasing ΔΔ14C and δ13C values... |
| Tipo: Text |
Palavras-chave: Radiocarbon; Ventilation; Southern Ocean; Younger Dryas; Carbon cycle; Indian Ocean. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00611/72351/71258.pdf |
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| Mahiques,Michel M.; Sousa,Silvia H.M.; Burone,Leticia; Nagai,Renata H.; Silveira,Ilson C.A.; Figueira,Rubens C.L.; Soutelino,Rafael G.; Ponsoni,Leandro; Klein,Daniel A.. |
| The aim of this work was to generate an inventory of the data on radiocarbon datings obtained from sediments of the São Paulo Bight (southern Brazilian upper margin) and to analyze the data in terms of Late Quaternary sedimentary processes and sedimentation rates. A total of 238 radiocarbon datings from materials collected using differents ampling procedures was considered for this work. The sedimentation rates varied from less than 2 to 68 cm.kyr-1. The highest sedimentation rate values were found in a low-energy (ría type) coastal system as well as in the upwelling zones of Santa Catarina and Cabo Frio. The lowest rates were found on the outer shelf and upper slopes. Our results confirm the strong dependency of the shelf currents, with an emphasis to the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Continental margin; Quaternary; Radiocarbon; Sea-level; Sedimentation. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652011000300006 |
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