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| Lallement,Mailén Elizabeth; Juárez,Santiago Martín; Macchi,Patricio Jorge; Vigliano,Pablo Horacio. |
| Volcanic eruptions are natural phenomena with the most diverse and varied consequences, and have important effects on both terrestrial and aquatic environments. On June 4th, 2011 the volcanic Puyehue Cordón-Caulle complex (2.236 masl, 40º 32´ S-72º 2´ W, Chile) erupted explosively ejecting on the first day, 950 million metric tons of ashes into the atmosphere. Due to predominant westerly winds, 24 million hectares of Argentinian Patagonia were covered by the ashfall. We studied three streams in northwestern Patagonia in order to explore the ash fall impact and possible recovery processes in water quality and macroinvertebrate communities. We selected three streams representing maximum, intermediate and minimum ash deposition levels. For each stream, we... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Volcanic ash; Impact; Arthropods; Functional feeding groups; Water quality. |
| Ano: 2014 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2014000100008 |
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| Balseiro,Esteban; Souza,María S.; Serra Olabuenaga,Ignacio; Wolinski,Laura; Bastidas Navarro,Marcela; Laspoumaderes,Cecilia; Modenutti,Beatriz. |
| We studied the effect of volcanic ash on the crustacean zooplankton (mainly cladocerans) in the Andean North-Patagonian lakes that were affected by the eruption of the Puyehue-Cordón Caulle complex. The study was carried out at three different scales: sub cellular, population and ecosystemic. Cladocerans are filter feeding organisms that cannot distinguish between food (algae less than 30 µm) and suspended ash, therefore when feeding they ingest this material. The ash affected negatively the individuals at a biochemical level, increasing the oxidative stress reacting enzymes like Glutation-S-transferase and the biomarker Acetyl cholinesterase. At the population level, we recorded a decrease in survival and fecundity, in particular, when ash concentration... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Volcanic ash; Cladocerans; Oxidative stress; Survivorship; Trophic level. |
| Ano: 2014 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2014000100009 |
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| Dang, H.; Li, J.; Zhang, X.; Li, T.; Tian, F.; Jin, W.. |
| The ecological characteristics of the deep-sea amoA-encoding archaea (AEA) are largely unsolved. Our aim was to study the diversity, structure and distribution of the AEA community in the sediments of the tropical West Pacific Continental Margin, to develop a general view of the AEA biogeography in the deep-sea extreme environment. Archaeal amoA clone libraries were constructed. Diverse and novel amoA sequences were identified, with the Bohol Sea, Bashi Strait and Sibuyan Sea harbouring the highest and the Bicol Shelf the lowest AEA diversity. Phylogenetic and statistical analyses illustrate a heterogeneous distribution of the AEA community, probably caused by the differential distribution of the terrestrial or estuarine AEA in the various sampling sites.... |
| Tipo: Text |
Palavras-chave: Ammonia-oxidizing archaea; AmoA-encoding archaea; Biogeography; Deep-sea sediment; Extremophile; Philippine Sea; Volcanic ash; West Pacific Continental Margin. |
| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00220/33077/31534.pdf |
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| Abbott, P. M.; Austin, W. E. N.; Davies, S. M.; Pearce, N. J. G.; Rasmussen, T. L.; Wastegard, S.; Brendryen, J.. |
| Previous studies of marine sequences from the Faroe Islands region have identified a series of coarse-grained tephra horizons deposited during Marine Isotope Stage (MIS) 5. Here we reassess the MIS 5 tephrostratigraphy of the Faroe Islands region and focus on the cryptotephra deposits preserved within the fine-grained fraction of marine core LINK 16. We also extend the record to encompass the late MIS 6 and early MIS 4 periods. A density separation technique, commonly used for tephra investigations in lacustrine settings but rarely applied to marine sediments, is utilised to explore the fine-grained material and EPMA and LA-ICP-MS are employed to determine the major and trace element composition of individual tephra shards. In total, 3 basaltic and 3... |
| Tipo: Text |
Palavras-chave: Volcanic ash; Iceland; Marine sequences; Isochrons; Palaeoclimatic synchronisation. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00290/40096/38832.pdf |
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