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| Bard, Edouard; Menot, Guillemette; Rostek, Frauke; Licari, Laetitia; Boening, Philipp; Edwards, R. Lawrence; Cheng, Hai; Wang, Yongjin; Heaton, Timothy J.. |
| We present a new record of radiocarbon ages measured by accelerator mass spectrometry (AMS) on a deep-sea core collected off the Pakistan Margin. The C-14 ages measured on the planktonic foraminifera Globigerinoides ruber from core MD04-2876 define a high and stable sedimentation rate on the order of 50 cm/kyr over the last 50 kyr. The site is distant from the main upwelling zone of the western Arabian Sea where C-14 reservoir age is large and may be variable. Many independent proxies based on elemental analyses, mineralogy, biomarkers, isotopic proxies, and foraminiferal abundances show abrupt changes correlative with Dansgaard-Oeschger and Heinrich events. It is now common knowledge that these climatic events also affected the Arabian Sea during the last... |
| Tipo: Text |
Palavras-chave: Berian Margin; Pakistan Margin; 14C; Calibration. |
| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00264/37569/35852.pdf |
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| Ronge, Thomas Alexander. |
| Reconstructions on Antarctic ice cores revealed pronounced, millennial-scale variabilities in atmospheric CO2 over the past 800,000 years (e.g. Lüthi et al., 2008; Monnin et al., 2001; Petit et al., 1999; Raynaud et al., 2005; Siegenthaler et al., 2005). Despite these variabilities are known for several decades, the mechanisms, driving these patterns are still not fully resolved. As the ocean contains up to 60 times more carbon than the entire atmosphere, it is considered to be a major driver of the atmospheric CO2 levels (Broecker, 1982): Storing CO2 during glacials, releasing it during deglaciations. Because changes in the global thermohaline circulation are thought to operate on glacial/interglacial timescales, it has been suggested that during... |
| Tipo: Text |
Palavras-chave: 14C; Ventilation; Atmospheric CO2; AAIW; UCDW; LCDW; AABW. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00493/60453/63898.pdf |
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| Silva,Vinicius Evangelista; Silva,Alexandre Christofaro; Pereira,Rosana Cristina; Camargo,Plínio Barbosa de; Silva,Bárbara Pereira Christofaro; Barral,Uidemar Morais; Mendonça Filho,Carlos Victor. |
| A matéria orgânica do solo (MOS) é um dos grandes reservatórios de carbono (C) da Terra e constitui um dos principais componentes do ciclo do C. Turfeiras, ambientes acumuladores de MOS, são produto da decomposição de vegetais, que se desenvolvem e se acumulam em ambientes saturados com água, sendo o estádio inicial da sequência de carbonificação. A fitomassa participa de forma marcante no ciclo global do C, armazenando em torno de 85 % de todo o C terrestre acima do solo. O tecido vegetal é composto principalmente por lignina, celulose e hemicelulose, constituindo até 85 % da biomassa seca. As plantas discriminam C de forma diferenciada, em razão de seu ciclo fotossintético (C3, C4 e CAM). As turfeiras da Serra do Espinhaço Meridional (SdEM-MG) são... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Organossolo; Δ13C; 14C; Campo; Floresta; Ciclo do carbono. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832013000100013 |
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