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Duputel, Z., J. Vergne, L. Rivera, G. Wittlinger, V. Farra, and G. Hetényi. (2016). The 2015 Gorkha earthquake: A large event illuminating the Main Himalayan Thrust fault. Geophysical research letters, 43(6), 2016GL068083.
Abstract: The 2015 Gorkha earthquake sequence provides an outstanding opportunity to better characterize the geometry of the Main Himalayan Thrust (MHT). To overcome limitations due to unaccounted lateral heterogeneities, we perform Centroid Moment Tensor inversions in a 3-D Earth model for the main shock and largest aftershocks. In parallel, we recompute S-to-P and P-to-S receiver functions from the Hi-CLIMB data set. Inverted centroid locations fall within a low-velocity zone at 10–15 km depth and corresponding to the subhorizontal portion of the MHT that ruptured during the Gorkha earthquake. North of the main shock hypocenter, receiver functions indicate a north dipping feature that likely corresponds to the midcrustal ramp connecting the flat portion to the deep part of the MHT. Our analysis of the main shock indicates that long-period energy emanated updip of high-frequency radiation sources previously inferred. This frequency-dependent rupture process might be explained by different factors such as fault geometry and the presence of fluids.
Programme: 133
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Portugal S.J., Green J.A., Arnold W., Careau V., Dann P, Frappell P.B., Gremillet D., Handrich Y., Martin G.R., Ruf T., Guillemette M.M., Butler P.J. & L.G. Halsey. (2016). The Association between Resting, Activity and Daily Metabolic Rate in Free-Living Endotherms: No Universal Rule in Birds and Mammals.. Physiol. Biochem. Zool., 89(3), 251–261.
Abstract: Energy management models provide theories and predictions for how animals manage their energy budgets within their energetic constraints, in terms of their resting metabolic rate (RMR) and daily energy expenditure (DEE). Thus, uncovering what associations exist between DEE and RMR is key to testing these models. Accordingly, there is considerable interest in the relationship between DEE and RMR at both inter-and intraspecific levels. Interpretation of the evidence for particular energy management models is enhanced by also considering the energy spent specifically on costly activities (activity energy expenditure [AEE] = DEE 2 RMR). However, to date there have been few intraspecific studies investigating such patterns. Our aim was to determine whether there is a generality of intraspecific relationships among RMR, DEE, and AEE using long-term data sets for bird and mammal species. For mammals, we use minimum heart rate (f(H)), mean fH, and activity fH as qualitative proxies for RMR, DEE, and AEE, respectively. For the birds, we take advantage of calibration equations to convert fH into rate of oxygen consumption in order to provide quantitative proxies for RMR, DEE, and AEE. For all 11 species, the DEE proxy was significantly positively correlated with the RMR proxy. There was also evidence of a significant positive correlation between AEE and RMR in all four mammal species but only in some of the bird species. Our results indicate there is no universal rule for birds and mammals governing the relationships among RMR, AEE, and DEE. Furthermore, they suggest that birds tend to have a different strategy for managing their energy budgets from those of mammals and that there are also differences in strategy between bird species. Future work in laboratory settings or highly controlled field settings can tease out the environmental and physiological processes contributing to variation in energy management strategies exhibited by different species.Keywords
Programme: 394
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Amélineau, F., Grémillet, D., Bonnet, D., Le Bot, T., & Fort, J. . (2016). Where to Forage in the Absence of Sea Ice? Bathymetry As a Key Factor for an Arctic Seabird. Plos one, 11(7), e0157764.
Abstract: The earth is warming at an alarming rate, especially in the Arctic, where a marked decline in sea ice cover may have far-ranging consequences for endemic species. Little auks, endemic Arctic seabirds, are key bioindicators as they forage in the marginal ice zone and feed preferentially on lipid-rich Arctic copepods and ice-associated amphipods sensitive to the consequences of global warming. We tested how little auks cope with an ice-free foraging environment during the breeding season. To this end, we took advantage of natural variation in sea ice concentration along the east coast of Greenland. We compared foraging and diving behaviour, chick diet and growth and adult body condition between two years, in the presence versus nearby absence of sea ice in the vicinity of their breeding site. Moreover, we sampled zooplankton at sea when sea ice was absent to evaluate prey location and little auk dietary preferences. Little auks foraged in the same areas both years, irrespective of sea ice presence/concentration, and targeted the shelf break and the continental shelf. We confirmed that breeding little auks showed a clear preference for larger copepod species to feed their chick, but caught smaller copepods and nearly no ice-associated amphipod when sea ice was absent. Nevertheless, these dietary changes had no impact on chick growth and adult body condition. Our findings demonstrate the importance of bathymetry for profitable little auk foraging, whatever the sea-ice conditions. Our investigations, along with recent studies, also confirm more flexibility than previously predicted for this key species in a warming Arctic.
Programme: 388
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Fromant Aymeric, Carravieri Alice, Bustamante Paco, Labadie Pierre, Budzinski Hélène, Peluhet Laurent, Churlaud Carine, Chastel Olivier, Cherel Yves. (2016). Wide range of metallic and organic contaminants in various tissues of the Antarctic prion, a planktonophagous seabird from the Southern Ocean. Sci. Total Environ., 544, 754–764.
Abstract: Trace elements (n = 14) and persistent organic pollutants (POPs, n = 30) were measured in blood, liver, kidney, muscle and feathers of 10 Antarctic prions (Pachyptila desolata) from Kerguelen Islands, southern Indian Ocean, in order to assess their concentrations, tissue distribution, and inter-tissue and inter-contaminant relationships. Liver, kidney and feathers presented the highest burdens of arsenic, cadmium and mercury, respectively. Concentrations of cadmium, copper, iron, and zinc correlated in liver and muscle, suggesting that uptake and pathways of metabolism and storage were similar for these elements. The major POPs were 4,4′-DDE, mirex, PCB-153 and PCB-138. The concentrations and tissue distribution patterns of environmental contaminants were overall in accordance with previous results in other seabirds. Conversely, some Antarctic prions showed surprisingly high concentrations of BDE-209. This compound has been rarely observed in seabirds before, and its presence in Antarctic prions could be due to the species feeding habits or to the ingestion of plastic debris. Overall, the study shows that relatively lower trophic level seabirds (zooplankton-eaters) breeding in the remote southern Indian Ocean are exposed to a wide range of environmental contaminants, in particular cadmium, selenium and some emerging-POPs, which merits further toxicological investigations.
Programme: 109
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Laparie M., Vernon P., Cozic Y., Frenot Y., Renault D., Debat V.. (2016). Wing morphology of the active flyer Calliphora vicina (Diptera, Calliphoridae) during its invasion of a sub-antarctic archipelago where insect flightlessness is the rule. Biological journal of the linnean society, 119, 179–193.
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Legrand, M., X. Yang, S. Preunkert, and N. Theys . (2016). Year-round records of sea salt, gaseous, and particulate inorganic bromine in the atmospheric boundary layer at coastal (Dumont d’Urville) and central (Concordia) East Antarctic sites. J. Geophys. Res., 121(2), 997–1023.
Abstract: Multiple year-round records of bulk and size-segregated compositions of aerosol were obtained at the coastal Dumont d'Urville (DDU) and inland Concordia sites located in East Antarctica. They document the sea-salt aerosol load and composition including, for the first time in Antarctica, the bromide depletion of sea-salt aerosol relative to sodium with respect to seawater. In parallel, measurements of bromide trapped in mist chambers and denuder tubes were done to investigate the concentrations of gaseous inorganic bromine species. These data are compared to simulations done with an off-line chemistry transport model, coupled with a full tropospheric bromine chemistry scheme and a process-based sea-salt production module that includes both sea-ice-sourced and open-ocean-sourced aerosol emissions. Observed and simulated sea-salt concentrations sometime differ by up to a factor of 2 to 3, particularly at DDU possibly due to local wind pattern. In spite of these discrepancies, both at coastal and inland Antarctica, the dominance of sea-ice-related processes with respect to open ocean emissions for the sea-salt aerosol load in winter is confirmed. For summer, observations and simulations point out sea salt as the main source of gaseous inorganic bromine species. Investigations of bromide in snow pit samples do not support the importance of snowpack bromine emissions over the Antarctic Plateau. To evaluate the overall importance of the bromine chemistry over East Antarctica, BrO simulations were also discussed with respect data derived from GOME-2 satellite observations over Antarctica.
Programme: 414
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Legrand, M., X. Yang, S. Preunkert, and N. Theys. (2016). Year-round records of sea salt, gaseous, and particulate inorganic bromine in the atmospheric boundary layer at coastal (Dumont d'Urville) and central (Concordia) East Antarctic sites. J. Geophys. Res., 121(2), 997–1023.
Abstract: Multiple year-round records of bulk and size-segregated compositions of aerosol were obtained at the coastal Dumont d'Urville (DDU) and inland Concordia sites located in East Antarctica. They document the sea-salt aerosol load and composition including, for the first time in Antarctica, the bromide depletion of sea-salt aerosol relative to sodium with respect to seawater. In parallel, measurements of bromide trapped in mist chambers and denuder tubes were done to investigate the concentrations of gaseous inorganic bromine species. These data are compared to simulations done with an off-line chemistry transport model, coupled with a full tropospheric bromine chemistry scheme and a process-based sea-salt production module that includes both sea-ice-sourced and open-ocean-sourced aerosol emissions. Observed and simulated sea-salt concentrations sometime differ by up to a factor of 2 to 3, particularly at DDU possibly due to local wind pattern. In spite of these discrepancies, both at coastal and inland Antarctica, the dominance of sea-ice-related processes with respect to open ocean emissions for the sea-salt aerosol load in winter is confirmed. For summer, observations and simulations point out sea salt as the main source of gaseous inorganic bromine species. Investigations of bromide in snow pit samples do not support the importance of snowpack bromine emissions over the Antarctic Plateau. To evaluate the overall importance of the bromine chemistry over East Antarctica, BrO simulations were also discussed with respect data derived from GOME-2 satellite observations over Antarctica.
Programme: 1154
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Fort, J. & Grémillet, D. (2016). Écosystèmes marins – aspects généraux.
Abstract: In: Le Groenland – Climat, Ecologie, Société (Editeurs: Masson-Delmotte, V., Gauthier, E., Grémillet, D., Huctin, JM, Swingedouw, D.). Editions du CNRS
Programme: 388
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Manon Poirson. (2016). Étude des habitats côtiers rocheux des îles Kerguelen et bilan des connaissances dans le but de mettre en place un suivi à long terme des communautés benthiques.
Abstract: The Kerguelen Islands are part of the French Southern and Antarctic Lands (TAAF), headquartered in St. Pierre de la Reunion. The TAAF have created in October 2006 a nature reserve covering an area of 22,700 km² making it the largest reserve of France. The marine reserve area of 15,700 km² 4 times the size of the marine park of the Gulf of Lion; it is also a hot spot of marine diversity. The goal of the program is PROTEKER set up a marine observatory for the ecological and genetic monitoring of coastal biodiversity of the Kerguelen Islands and assessment of current and expected environmental changes on this biodiversity (Saucède et al). With the increasing risks due to climate warming on marine environments, many initiatives are in place, protecting the environment can not be done when one has gained a deep understanding of the medium. Monitoring of population structure in a conservation objective requires an initial inventory and regular quantitative and qualitative observations. Image analysis through photoQuad software makes the characterization of marine habitats fast and easily reproducible.
Programme: 1044
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Poirson M. (2016). Étude des habitats côtiers rocheux des îles Kerguelen et bilan des connaissances dans le but de mettre en place un suivi à long terme des communautés benthiques. Master 1.
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