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| Pessenda,Luiz C.R.; Saia,Soraya E.M.G.; Gouveia,Susy E.M.; Ledru,Marie-Pierre; Sifeddine,Abdelfettah; Amaral,Paula G.C.; Bendassolli,José A.. |
| This study presents paleoenvironmental data based on pollen, elemental and isotopic compositions of organic matter (TOC, N, d13C and d15N) and 14C dating of 170 cm lake sediment record. Samplings have been made in Lagoa Grande at Parque Estadual Turístico do Alto Ribeira - PETAR, Southern São Paulo State, Southeastern Brazil. The variations in relative frequencies (in percentage) of arboreal pollen along the core range between 40 and 80%. The d13C values ranged from -23 to -30 and C/N of ~10 to 15, indicating the contribution of terrestrial C3 plants and algae in the sediment organic matter. The d15N results presented values from 3 to 4.5, also suggesting a mixture of algae and terrestrial C3 plants. The 14C dating indicates modern age for the shallow... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lacustrine sediment; C and N isotopes; Pollen; Atlantic Forest; Last millennium; Little Ice Age. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652010000300019 |
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| Cronin, Tm; Dwyer, Gs; Kamiya, T; Schwede, S; Willard, Da. |
| We present paleoclimate evidence for rapid (< 100 years) shifts of similar to 2-4 degreesC in Chesapeake Bay (CB) temperature similar to 2100, 1600, 950, 650, 400 and 150 years before present (years BP) reconstructed from magnesium/calcium (Mg/Ca) paleothermometry. These include large temperature excursions during the Little Ice Age (similar to 1400-1900 AD) and the Medieval Warm Period (similar to 800-1300 AD) possibly related to changes in the strength of North Atlantic thermohaline circulation (THC). Evidence is presented for a long period of sustained regional and North Atlantic-wide warmth with low-amplitude temperature variability between similar to450. and 1000 AD. In addition to centennial-scale temperature shifts, the existence of numerous... |
| Tipo: Text |
Palavras-chave: Paleoclimatology; Holocene; Medieval Warm Period; Little Ice Age; 20th century climate; North Atlantic Oscillation. |
| Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/00225/33648/32092.pdf |
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| Saher, Margot H.; Gehrels, W. Roland; Barlow, Natasha L. M.; Long, Antony J.; Haigh, Ivan D.; Blaauw, Maarten. |
| We present a new, diatom-based sea-level reconstruction for Iceland spanning the last similar to 500 years, and investigate the possible mechanisms driving the sea-level changes. A sea-level reconstruction from near the Icelandic low pressure system is important as it can improve understanding of ocean atmosphere forcing on North Atlantic sea-level variability over multi-decadal to centennial timescales. Our reconstruction is from Vioarholmi salt marsh in Snafellsnes in western Iceland, a site from where we previously obtained a 2000-yr record based upon less precise sea-level indicators (salt-marsh foraminifera). The 20th century part of our record is corroborated by tide-gauge data from Reykjavik. Overall, the new reconstruction shows ca 0.6 m rise of... |
| Tipo: Text |
Palavras-chave: Diatoms; Ocean dynamics; Iceland; Little Ice Age; Sea-level rise; NAO. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00352/46283/45963.pdf |
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