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Carravieri Alice, Bustamante Paco, Tartu Sabrina, Meillère Alizée, Labadie Pierre, Budzinski Hélène, Peluhet Laurent, Barbraud Christophe, Weimerskirch Henri, Chastel Olivier, Cherel Yves, . (2014). Wandering albatrosses document latitudinal variations in the transfer of persistent organic pollutants and mercury to Southern Ocean predators.
. Environ. Sci. Technol., 48(24), 14746–55.
Abstract: Top marine predators are effective tools to monitor bioaccumulative contaminants in remote oceanic environments. Here, we used the wide-ranging wandering albatross Diomedea exulans to investigate potential geographical variations of contaminant transfer to predators in the Southern Ocean. Blood concentrations of 19 persistent organic pollutants and 14 trace elements were measured in a large number of individuals (N = 180) of known age, sex and breeding status from the subantarctic Crozet Islands. Wandering albatrosses were exposed to a wide range of contaminants, with notably high blood mercury concentrations. Contaminant burden was markedly influenced by latitudinal foraging habitats (inferred from blood δ(13)C values), with individuals feeding in warmer subtropical waters having lower concentrations of pesticides, but higher concentrations of mercury, than those feeding in colder subantarctic waters. Sexual differences in contaminant burden seemed to be driven by gender specialization in feeding habitats, rather than physiological characteristics, with females foraging further north than males. Other individual traits, such as adult age and reproductive status, had little effect on blood contaminant concentrations. Our study provides further evidence of the critical role of global distillation on organic contaminant exposure to Southern Ocean avian predators. In addition, we document an unexpected high transfer of mercury to predators in subtropical waters, which merits further investigation.
Keywords: Animals, Arsenic, Arsenic: blood, Birds, Birds: blood, Birds: physiology, Ecosystem, Environmental Monitoring, Female, Food Chain, Halogenated Diphenyl Ethers, Halogenated Diphenyl Ethers: blood, Hydrocarbons, Chlorinated, Hydrocarbons, Chlorinated: blood, Male, Metals, Heavy, Metals, Heavy: blood, Oceans and Seas, Reproduction, Water Pollutants, Chemical, Water Pollutants, Chemical: blood,
Programme: 109
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Duputel Zacharie, Rivera Luis, Kanamori Hiroo, Hayes Gavin, . (2012). W phase source inversion for moderate to large earthquakes (19902010)
. Geophysical Journal International , 189 (2 ), 1125–1147 .
Abstract: Rapid characterization of the earthquake source and of its effects is a growing field of interest. Until recently, it still took several hours to determine the first-order attributes of a great earthquake (e.g. Mw 7.5), even in a well-instrumented region. The main limiting factors were data saturation, the interference of different phases and the time duration and spatial extent of the source rupture. To accelerate centroid moment tensor (CMT) determinations, we have developed a source inversion algorithm based on modelling of the W phase, a very long period phase (1001000s) arriving at the same time as the P wave. The purpose of this work is to finely tune and validate the algorithm for large-to-moderate-sized earthquakes using three components of W phase ground motion at teleseismic distances. To that end, the point source parameters of all Mw 6.5 earthquakes that occurred between 1990 and 2010 (815 events) are determined using Federation of Digital Seismograph Networks, Global Seismographic Network broad-band stations and STS1 global virtual networks of the Incorporated Research Institutions for Seismology Data Management Center. For each event, a preliminary magnitude obtained from W phase amplitudes is used to estimate the initial moment rate function half duration and to define the corner frequencies of the passband filter that will be applied to the waveforms. Starting from these initial parameters, the seismic moment tensor is calculated using a preliminary location as a first approximation of the centroid. A full CMT inversion is then conducted for centroid timing and location determination. Comparisons with Harvard and Global CMT solutions highlight the robustness of W phase CMT solutions at teleseismic distances. The differences in Mw rarely exceed 0.2 and the source mechanisms are very similar to one another. Difficulties arise when a target earthquake is shortly (e.g. within 10 hr) preceded by another large earthquake, which disturbs the waveforms of the target event. To deal with such difficult situations, we remove the perturbation caused by earlier disturbing events by subtracting the corresponding synthetics from the data. The CMT parameters for the disturbed event can then be retrieved using the residual seismograms. We also explore the feasibility of obtaining source parameters of smaller earthquakes in the range 6.0 Mw < 6.5. Results suggest that the W phase inversion can be implemented reliably for the majority of earthquakes of Mw= 6 or larger.
Programme: 133
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Grémillet David, Prudor Aurélien, le Maho Yvon, Weimerskirch Henri, . (2012). Vultures of the Seas: Hyperacidic Stomachs in Wandering Albatrosses as an Adaptation to Dispersed Food Resources, including Fishery Wastes
. PLoS ONE, 7(6), e37834–.
Abstract: Animals are primarily limited by their capacity to acquire food, yet digestive performance also conditions energy acquisition, and ultimately fitness. Optimal foraging theory predicts that organisms feeding on patchy resources should maximize their food loads within each patch, and should digest these loads quickly to minimize travelling costs between food patches. We tested the prediction of high digestive performance in wandering albatrosses, which can ingest prey of up to 3 kg, and feed on highly dispersed food resources across the southern ocean. GPS-tracking of 40 wandering albatrosses from the Crozet archipelago during the incubation phase confirmed foraging movements of between 4754705 km, which give birds access to a variety of prey, including fishery wastes. Moreover, using miniaturized, autonomous data recorders placed in the stomach of three birds, we performed the first-ever measurements of gastric pH and temperature in procellariformes. These revealed surprisingly low pH levels (average 1.50±0.13), markedly lower than in other seabirds, and comparable to those of vultures feeding on carrion. Such low stomach pH gives wandering albatrosses a strategic advantage since it allows them a rapid chemical breakdown of ingested food and therefore a rapid digestion. This is useful for feeding on patchy, natural prey, but also on fishery wastes, which might be an important additional food resource for wandering albatrosses.
Programme: 109
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Hullé M., Lebouvier M., Marais A., Frenot Y. & Renault D. (2010). Vulnerability of native communities to invasive Insects and climate change on Kerguelen Islands. IPY Science Conference, Oslo, Norway, 08-12/06/2010.
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Renault D. (2012). Vulnerability of native communities to invasive insects and climate change in sub-Antarctic islands – Projet EVINCE (VMC 2007), Séminaire de restitution et d’avancement des projets ANR sur les “Changements Environnementaux”, Bordeaux, France, 21-22 mai 2012.
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Renault D., Lebouvier M., Hullé M. & Frenot Y. (2009). Vulnerability of native communities to invasive insects and climate change in sub-Antarctic islands.
Abstract: BIOLIEF World Conference on Biological Invasion and Ecosystem Functionning, Porto, Portugal, 27-30/10/2009
Programme: 136
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Hullé M., Lebouvier M., Marais A., Frenot Y. & Renault D. (2010). Vulnérabilité des écosystèmes subantarctiques face aux invasions d’insectes et aux changements climatiques.7ème Conférence Internationale Francophone d’Entomologie, Louvain la Neuve, Belgique, 05-10/07/2010.
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Hullé M., Lebouvier M., Laparie M., Marais A., Cozic Y., Lalouette L., Vernon P., Candresse T., Frenot Y., Renault D. (2011). Vulnérabilité des communautés natives face aux insectes invasifs et au changement climatique dans les îles sub-antarctiques.
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Abstract: 7èmes journées scientifiques du CNFRA, Paris, France, 19-20/05/2011
Programme: 136
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Salamatin A.N., Tsiganova E.A., Lipenkov V.Y. & Petit J.R. (2005). Vostok (Antarctica) ice-core time scale from datings of different origins. Annals of glaciology, 39, 83–292.
Abstract: Seventh International Symposium on Antarctic Glaciology
Programme: 355
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Brigitte Van Vliet-Lanoë, Oskar Knudsen, Agust Guðmundsson, Hervé Guillou, Gilles Chazot, Jessica Langlade, Céline Liorzou, Philippe Nonnotte. (2020). Volcanoes and climate: the triggering of preboreal Jökulhlaups in Iceland (Vol. 109).
Abstract: The Early Holocene (12–8.2 cal ka) deglaciation and pulsed warming was associated in Iceland with two major generations of jökulhlaups around the Vatna ice-cap (Vatnajökull), at ca 11.4–11.2 cal ka and ca 10.4–9.9 cal ka, and major tephra emissions from the Grímsvötn and Bárðarbunga subglacial volcanoes. The earliest flood events were recorded inland during the Middle Younger Dryas and their deposits were overlain by the Early Preboreal Vedde Ash (11.8 cal ka). The first Holocene flood events (ca 11.4–11.2 cal ka) are issued from a glacial advance. The second, and major, set of floods was partly driven by the Erdalen cold events and advances (10.1–9.7 10Be ka) initially issued from the Bárðarbunga (10.4, 10.1–9.9 ka) and Grímsvötn volcanoes (Saksunarvatn tephra complex, ca. 10.2–9.9 cal ka). These floods were also fed by the residual glacio-isostatic depressions below the Vatnajökull that enabled the storage of meltwaters in large subglacial lakes or aquifers until ca. 9.3 cal ka. This storage was enhanced by ice-damming and permafrost, especially during the twinned Erdalen events. Due to the glacio-isostatic rebound, the general slope was nearly flat, and the valley was partly filled with sediments until ca 10.8 cal ka. Temporary lacustrine deposits in this valley resulted from the very broad splay of waters as for the ca 11.2 cal ka and ca 10.1–9.9 cal ka flood, due to regional permafrost. These floods had a potential duration of several months as they were mostly fed by climate-driven meltwater. The maximal volume evacuated by these events did not greatly exceed 1 × 106 m3 s−1 from the flood-affected transverse profile of the valleys that remain partly filled with sediments.
Programme: 316
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