Ekström, Göran & Nettles, Meredith. (2014). Long-Period Moment-Tensor Inversion: The Global CMT Project.
Abstract: Book title : Encyclopedia of Earthquake Engineering
Programme: 133
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Lyubushin A A, . (2014). Wavelet-based coherence measures of global seismic noise properties
. Journal of Seismology, 19(2), 329–340.
Abstract: The coherent behavior of four parameters characterizing the global field of low-frequency (periods from 2 to 500 min) seismic noise is studied. These parameters include generalized Hurst exponent, multifractal singularity spectrum support width, the normalized entropy of variance, and kurtosis. The analysis is based on the data from 229 broadband stations of GSN, GEOSCOPE, and GEOFON networks for a 17-year period from the beginning of 1997 to the end of 2013. The entire set of stations is subdivided into eight groups, which, taken together, provide full coverage of the Earth. The daily median values of the studied noise parameters are calculated in each group. This procedure yields four 8-dimensional time series with a time step of 1 day with a length of 6209 samples in each scalar component. For each of the four 8-dimensional time series, a multiple correlation measure is estimated, which is based on computing robust canonical correlations for the Haar wavelet coefficients at the first detail level within a moving time window of the length 365 days. These correlation measures for each noise property demonstrate essential increasing starting from 2007 to 2008 which was continued till the end of 2013. Taking into account a well-known phenomenon of noise correlation increasing before catastrophes, this increasing of seismic noise synchronization is interpreted as indicators of the strongest (magnitudes not less than 8.5) earthquakes activation which is observed starting from the Sumatra mega-earthquake of 26 Dec 2004. This synchronization continues growing up to the end of the studied period (2013), which can be interpreted as a probable precursor of the further increase in the intensity of the strongest earthquakes all over the world.
Programme: 133
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Tixier Paul, Gasco Nicolas, Poupart Timothée, Guinet Christophe. (2014). Photo-Identification Catalogue 2014
Type-D killer whales of the Crozet Islands.
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Roquet Fabien, Williams Guy, Hindell Mark A, Harcourt Rob, McMahon Clive, Guinet Christophe, Charrassin Jean-Benoit, Reverdin Gilles, Boehme Lars, Lovell Phil, Fedak Mike, . (2014). A Southern Indian Ocean database of hydrographic profiles obtained with instrumented elephant seals.
. Scientific data, 1, 140028.
Abstract: The instrumentation of southern elephant seals with satellite-linked CTD tags has offered unique temporal and spatial coverage of the Southern Indian Ocean since 2004. This includes extensive data from the Antarctic continental slope and shelf regions during the winter months, which is outside the conventional areas of Argo autonomous floats and ship-based studies. This landmark dataset of around 75,000 temperature and salinity profiles from 20-140 °E, concentrated on the sector between the Kerguelen Islands and Prydz Bay, continues to grow through the coordinated efforts of French and Australian marine research teams. The seal data are quality controlled and calibrated using delayed-mode techniques involving comparisons with other existing profiles as well as cross-comparisons similar to established protocols within the Argo community, with a resulting accuracy of ±0.03 °C in temperature and ±0.05 in salinity or better. The data offer invaluable new insights into the water masses, oceanographic processes and provides a vital tool for oceanographers seeking to advance our understanding of this key component of the global ocean climate.
Keywords: Animals, Databases, Factual, Indian Ocean, Oceanography, Oceanography: methods, Seals, Earless,
Programme: 109
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Richard Gaëtan, Vacquié-Garcia Jade, Jouma'a Joffrey, Picard Baptiste, Génin Alexandre, Arnould John P Y, Bailleul Frédéric, Guinet Christophe, . (2014). Variation in body condition during the post-moult foraging trip of southern elephant seals and its consequences on diving behaviour.
. J. Exp. Biol., 217(Pt 14), 2609–19.
Abstract: Mature female southern elephant seals (Mirounga leonina) come ashore only in October to breed and in January to moult, spending the rest of the year foraging at sea. Mature females may lose as much as 50% of their body mass, mostly in lipid stores, during the breeding season due to fasting and lactation. When departing to sea, post-breeding females are negatively buoyant, and the relative change in body condition (i.e. density) during the foraging trip has previously been assessed by monitoring the descent rate during drift dives. However, relatively few drift dives are performed, resulting in low resolution of the temporal reconstruction of body condition change. In this study, six post-breeding females were equipped with time-depth recorders and accelerometers to investigate whether changes in active swimming effort and speed could be used as an alternative method of monitoring density variations throughout the foraging trip. In addition, we assessed the consequences of density change on the swimming efforts of individuals while diving and investigated the effects on dive duration. Both descent swimming speed and ascent swimming effort were found to be strongly correlated to descent rate during drift dives, enabling the fine-scale monitoring of seal density change over the whole trip. Negatively buoyant seals minimized swimming effort during descents, gliding down at slower speeds, and reduced their ascent swimming effort to maintain a nearly constant swimming speed as their buoyancy increased. One per cent of seal density variation over time was found to induce a 20% variation in swimming effort during dives with direct consequences on dive duration.
Keywords: Animals, Behavior, Animal, Behavior, Animal: physiology, Biomechanical Phenomena, Body Composition, Diving, Diving: physiology, Female, Oceans and Seas, Seals, Earless, Seals, Earless: physiology, Swimming, Swimming: physiology, Telemetry,
Programme: 109
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Patrick Samantha C, Weimerskirch Henri, . (2014). Consistency pays: sex differences and fitness consequences of behavioural specialization in a wide-ranging seabird.
. 1744-9561, 10(10), 20140630.
Abstract: Specialists and generalists often coexist within a single population, but the biological drivers of individual strategies are not fully resolved. When sexes differ in their foraging strategy, this can lead them to different environmental conditions and stability across their habitat range. As such, sexual segregation, combined with dominance, may lead to varying levels of specialization between the sexes. Here, we examine spatial and temporal niche width (intraindividual variability in aspects of foraging behaviour) of male and female black-browed albatrosses (Thalassarche melanophrys), and its consequences for fitness. We show that females, where maximum foraging range is under fluctuating selection, exhibit more variable behaviours and appear more generalist than males, who are under directional selection to forage close to the colony. However within each sex, successful birds had a much narrower niche width across most behaviours, suggesting some specialization is adaptive in both sexes. These results demonstrate that while there are sex differences in niche width, the fitness benefit of specialization in spatial distribution is strong in this wide-ranging seabird.
Keywords: Animals, Birds, Birds: physiology, Environment, Feeding Behavior, Feeding Behavior: physiology, Female, Male, Predatory Behavior, Reproduction, Reproduction: physiology, Sex Factors,
Programme: 109
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Goutte A, Charrassin JB, Cherel Y, Carravieri A, De Grissac S, Massé G, . (2014). Importance of ice algal production for top predators: new insights using sea-ice biomarkers
. Mar. Ecol. Prog. Ser., 513, 269–275.
Abstract: ABSTRACT: Antarctic seals and seabirds are strongly dependent on sea-ice cover to complete their life history. In polar ecosystems, sea ice provides a habitat for ice-associated diatoms that ensures a substantial production of organic matter. Recent studies have presented the potential of highly branched isoprenoids (HBIs) for tracing carbon flows from ice algae to higher-trophic-level organisms. However, to our knowledge, this new method has never been applied to sub-Antarctic species and Antarctic seals. Moreover, seasonal variations in HBI levels have never been investigated in Antarctic predators, despite a likely shift in food source from ice-derived to pelagic organic matter after sea-ice retreat. In the present study, we described HBI levels in a community of seabirds and seals breeding in Adélie Land, Antarctica. We then validated that sub-Antarctic seabirds had lower levels of diene, a HBI of sea-ice diatom origin, and higher levels of triene, a HBI of phytoplanktonic origin, compared with Antarctic seabirds. Finally, we explored temporal changes in HBI levels after the ice break up in summer. The level of diene relative to triene in Adélie penguin chicks increased and then declined during the breeding season, which was consistent with the short and intense proliferation of sea-ice algae in spring, followed by the pelagic phytoplankton bloom in summer. HBI biomarkers in Antarctic seabirds and seals thus indicate a shift from ice-algal derived organic matter to a pelagic carbon source during the summer breeding season.
Programme: 109
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Carravieri Alice, Cherel Yves, Blévin Pierre, Brault-Favrou Maud, Chastel Olivier, Bustamante Paco, . (2014). Mercury exposure in a large subantarctic avian community.
. Environ. Pollut., 190, 51–7.
Abstract: Mercury (Hg) contamination poses potential threats to ecosystems worldwide. In order to study Hg bioavailability in the poorly documented southern Indian Ocean, Hg exposure was investigated in the large avian community of Kerguelen Islands. Adults of 27 species (480 individuals) showed a wide range of feather Hg concentrations, from 0.4 ± 0.1 to 16.6 ± 3.8 μg g(-1) dry weight in Wilson's storm petrels and wandering albatrosses, respectively. Hg concentrations increased roughly in the order crustacean- < fish- ≤ squid- ≤ carrion-consumers, confirming that diet, rather than taxonomy, is an important driver of avian Hg exposure. Adults presented higher Hg concentrations than chicks, due to a longer duration of exposure, with the only exception being the subantarctic skua, likely because of feeding habits' differences of the two age-classes in this species. High Hg concentrations were reported for three species of the poorly known gadfly petrels, which merit further investigation.
Keywords: Animals, Birds, Birds: metabolism, Ecosystem, Environmental Monitoring, Environmental Pollutants, Environmental Pollutants: analysis, Environmental Pollutants: metabolism, Feathers, Feathers: chemistry, Food Chain, Humans, Mercury, Mercury: analysis, Mercury: metabolism,
Programme: 109
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Carravieri Alice, Bustamante Paco, Churlaud Carine, Fromant Aymeric, Cherel Yves, . (2014). Moulting patterns drive within-individual variations of stable isotopes and mercury in seabird body feathers: implications for monitoring of the marine environment
. Mar. Biol., 161(4), 963–968.
Abstract: One major limitation in the use of body feathers of seabirds as a monitoring tool of the trophic structure and contamination levels of marine ecosystems is the degree of heterogeneity in feather chemical composition within individuals. Here, we tested the hypothesis that moulting patterns drive body feather heterogeneity, with synchronous moult minimizing within-individual variations, in contrast to asynchronous feather growth. Chicks of white-chinned petrels Procellaria aequinoctialis (representative of bird chicks) and adults of king penguins Aptenodytes patagonicus (representative of adult penguins) that moult their body feathers synchronously showed very low within-individual variations in their feather δ13C and δ15N values and mercury (Hg) concentrations. By contrast, body feathers of adults of Antarctic prions Pachyptila desolata (representative of adult seabirds with asynchronous feather growth during a protracted moult) presented much higher within-individual variances for the three parameters. These findings have three important implications for birds presenting a synchronous body moult. (1) They suggest that all body feathers from the same individual have identical δ13C and δ15N values and Hg content. (2) They predict negligible within-individual variations in the body feather values of other useful stable isotopes, such as δ2H and δ34S, as well as in the concentrations of other compounds that are deposited in the keratin structure. (3) Analysis of one or any number of pooled body feathers is equally representative of the individual. In conclusion, we recommend that long-term routine monitoring investigations focus on birds presenting synchronous rather than asynchronous moult of body feathers both in marine and terrestrial environments. This means targeting chicks rather than adults and, for seabirds, penguins rather than adults of flying species.
Programme: 109
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Thiers Laurie. (2014). Utilisation des prédateurs supérieurs pour déterminer les zones d’importance pour la biodiversité : comparaison de différentes méthodes de mise en évidence de “hotspots”. .
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