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Author Emilie Portier, Denis Mercier, Armelle Decaulne, Etienne Cossart doi  openurl
  Title Schmidt-hammer exposure-age dating of seven paraglacial rock-slope failures in the Bolungarvík-Suðureyri area (Westfjords, Iceland) Type Journal
  Year (down) 2024 Publication Geomorphology Abbreviated Journal  
  Volume 457 Issue Pages 109230  
  Keywords Deglaciation Holocene Landslide Rock-slope failures Schmidt-hammer exposure-age dating  
  Abstract Many rock-slope failures (RSF) impact Iceland's Westfjords morphology. Five RSF areas, totalling seven RSFs, were studied in the western fjords around Bolungarvík-Suðureyri: Óshólar, Minni-Hlið, Meira-Hraun, the Vatnadalur valley and part of the Sunddalur valley. The aim of this article is to provide chronological data of the RSFs and to subsequently obtain a better chronosequence of post-glacial events, none of which have yet been dated in the Westfjords. More particularly, we discuss a paraglacial hypothesis of their occurrence. For this purpose, the Schmidt-hammer exposure-age dating (SHD) method is used on the RSF deposits, and the rebound values obtained from the impacted blocks are converted to age estimates using radiocarbon ages obtained from the different sites in order to calculate a SHD age calibration. Then, we establish a chronology of the setting up of the events. In this way, seven RSFs have been dated and different chronological generations of deposit emplacement have been exhibited for some of them. Thus, various periods of instability affected mountain slopes. The Óshólar RSF is thought to have been deposited firstly at around 12,500 cal BP, the Minni-Hlið RSF at ∼9800 cal BP, the Meira-Hraun RSF at ∼8700 cal BP, the Vatnadalur RSFs at ∼9000 cal BP, ∼ 6900 cal BP, and ∼ 4300 cal BP, and the Sunddalur RSF at ∼9600 cal BP. These RSFs therefore correspond to so-called paraglacial events, which took place at the beginning of deglaciation of the area during the first half of the Holocene.  
  Programme 1266  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0169-555X ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8759  
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Author Yann Méheust, Karine Delord, Anne-Sophie Bonnet-Lebrun, Thierry Raclot, Julien Vasseur, Jimmy Allain, Virgil Decourteillle, Charles-André Bost, Christophe Barbraud doi  openurl
  Title Human infrastructures correspond to higher Adélie penguin breeding success and growth rate Type Journal
  Year (down) 2024 Publication Oecologia Abbreviated Journal  
  Volume 204 Issue 3 Pages 675-688  
  Keywords Antarctica Breeding habitat quality Human disturbance Population dynamics Population monitoring Pygoscelis adeliae  
  Abstract Anthropogenic activities generate increasing disturbance in wildlife especially in extreme environments where species have to cope with rapid environmental changes. In Antarctica, while studies on human disturbance have mostly focused on stress response through physiological and behavioral changes, local variability in population dynamics has been addressed more scarcely. In addition, the mechanisms by which breeding communities are affected around research stations remain unclear. Our study aims at pointing out the fine-scale impact of human infrastructures on the spatial variability in Adélie penguin (Pygoscelis adeliae) colonies dynamics. Taking 24 years of population monitoring, we modeled colony breeding success and growth rate in response to both anthropic and land-based environmental variables. Building density around colonies was the second most important variable explaining spatial variability in breeding success after distance from skua nests, the main predators of penguins on land. Building density was positively associated with penguins breeding success. We discuss how buildings may protect penguins from avian predation and environmental conditions. The drivers of colony growth rate included topographical variables and the distance to human infrastructures. A strong correlation between 1-year lagged growth rate and colony breeding success was coherent with the use of public information by penguins to select their initial breeding site. Overall, our study brings new insights about the relative contribution and ecological implications of human presence on the local population dynamics of a sentinel species in Antarctica.  
  Programme 1091  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1432-1939 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8763  
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Author Marta Cruz-Flores, Jérémy Lemaire, Maud Brault-Favrou, Signe Christensen-Dalsgaard, Carine Churlaud, Sébastien Descamps, Kyle Elliott, Kjell Einar Erikstad, Alexey Ezhov, Maria Gavrilo, David Grémillet, Gaël Guillou, Scott Hatch, Nicholas Per Huffeldt, Alexander S. Kitaysky, Yann Kolbeinsson, Yuri Krasnov, Magdalene Langset, Sarah Leclaire, Jannie F. Linnebjerg, Erlend Lorentzen, Mark L. Mallory, Flemming R. Merkel, William Montevecchi, Anders Mosbech, Allison Patterson, Samuel Perret, Jennifer F. Provencher, Tone K. Reiertsen, Heather Renner, Hallvard Strøm, Akinori Takahashi, Jean-Baptiste Thiebot, Thorkell Lindberg Thórarinsson, Alexis Will, Paco Bustamante, Jérôme Fort doi  openurl
  Title Spatial distribution of selenium-mercury in Arctic seabirds Type Journal
  Year (down) 2024 Publication Environmental Pollution Abbreviated Journal  
  Volume 343 Issue Pages 123110  
  Keywords Atlantic-Arctic Black-legged kittiwake Blood Brünnich's guillemot Pacific-Arctic Stable isotopes Thick-billed murre Toxics  
  Abstract Mercury (Hg) is a metallic trace element toxic for humans and wildlife that can originate from natural and anthropic sources. Hg spatial gradients have been found in seabirds from the Arctic and other oceans, suggesting contrasting toxicity risks across regions. Selenium (Se) plays a protective role against Hg toxicity, but its spatial distribution has been much less investigated than that of Hg. From 2015 to 2017, we measured spatial co-exposure of Hg and Se in blood samples of two seabird species, the Brünnich's guillemot (Uria lomvia) and the black-legged kittiwake (Rissa tridactyla) from 17 colonies in the Arctic and subarctic regions, and we calculated their molar ratios (Se:Hg), as a measure of Hg sequestration by Se and, therefore, of Hg exposure risk. We also evaluated concentration differences between species and ocean basins (Pacific-Arctic and Atlantic-Arctic), and examined the influence of trophic ecology on Hg and Se concentrations using nitrogen and carbon stable isotopes. In the Atlantic-Arctic ocean, we found a negative west-to-east gradient of Hg and Se for guillemots, and a positive west-to-east gradient of Se for kittiwakes, suggesting that these species are better protected from Hg toxicity in the European Arctic. Differences in Se gradients between species suggest that they do not follow environmental Se spatial variations. This, together with the absence of a general pattern for isotopes influence on trace element concentrations, could be due to foraging ecology differences between species. In both oceans, the two species showed similar Hg concentrations, but guillemots showed lower Se concentrations and Se:Hg than kittiwakes, suggesting a higher Hg toxicity risk in guillemots. Within species, neither Hg, nor Se or Se:Hg differed between both oceans. Our study highlights the importance of considering Se together with Hg, along with different species and regions, when evaluating Hg toxic effects on marine predators in international monitoring programs.  
  Programme 388  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0269-7491 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8767  
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Author Julian E. Beaman, Craig R. White, Manon Clairbaux, Samuel Perret, Jérôme Fort, David Grémillet doi  openurl
  Title Cold adaptation does not handicap warm tolerance in the most abundant Arctic seabird Type Journal
  Year (down) 2024 Publication Proceedings of the Royal Society B: Biological Sciences Abbreviated Journal  
  Volume 291 Issue 2015 Pages 20231887  
  Keywords Animal energetics dovekie ecophysiology evolutionary legacy global warming phylogenic analyses  
  Abstract Arctic birds and mammals are physiologically adapted to survive in cold environments but live in the fastest warming region on the planet. They should therefore be most threatened by climate change. We fitted a phylogenetic model of upper critical temperature (TUC) in 255 bird species and determined that TUC for dovekies (Alle alle; 22.4°C)—the most abundant seabird in the Arctic—is 8.8°C lower than predicted for a bird of its body mass (150 g) and habitat latitude. We combined our comparative analysis with in situ physiological measurements on 36 dovekies from East Greenland and forward-projections of dovekie energy and water expenditure under different climate scenarios. Based on our analyses, we demonstrate that cold adaptation in this small Arctic seabird does not handicap acute tolerance to air temperatures up to at least 15°C above their current maximum. We predict that climate warming will reduce the energetic costs of thermoregulation for dovekies, but their capacity to cope with rising temperatures will be constrained by water intake and salt balance. Dovekies evolved 15 million years ago, and their thermoregulatory physiology might also reflect adaptation to a wide range of palaeoclimates, both substantially warmer and colder than the present day.  
  Programme 388  
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  Notes Approved yes  
  Call Number Serial 8776  
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Author Armelle Poisson, Thierry Boulinier, Laure Bournez, Gaëlle Gonzalez, Camille V. Migné, Sara Moutailler, Bruno Faivre, Raphaëlle Métras doi  openurl
  Title Tick-borne zoonotic flaviviruses and Borrelia infections in wildlife hosts: What have field studies contributed? Type Journal
  Year (down) 2024 Publication One Health Abbreviated Journal  
  Volume 18 Issue Pages 100747  
  Keywords Flavivirus Host Reservoir Sentinel Tick-borne diseases Wildlife  
  Abstract Tick-borne flaviviruses and Borrelia spp. are globally spread pathogens of zoonotic potential that are maintained by a transmission cycle at the interface between ticks and vertebrate hosts, mainly wild animals. Aside data on pathogen burden in ticks, information on the status of various hosts relative to infection is important to acquire. We reviewed how those infections have been studied in wildlife host species in the field to discuss how collected data provided relevant epidemiological information and to identify needs for further studies. The literature was screened for observational studies on pathogen or antibody detection for tick-borne Borrelia spp. and flaviviruses in wildlife host animals. Overall, Borrelia spp. were more studied (73% of case studies, representing 297 host species) than flaviviruses (27% of case studies, representing 114 host species). Studies on both Borrelia spp. and flaviviruses focused mainly on the same species, namely bank vole and yellow-necked mouse. Most studies were order-specific and cross-sectional, reporting prevalence at various locations, but with little insight into the underlying epidemiological dynamics. Host species with potential to act as reservoir hosts of these pathogens were neglected, notably birds. We highlight the necessity of collecting both demographics and infection data in wildlife studies, and to consider communities of species, to better estimate zoonotic risk potential in the One Health context.  
  Programme 1151  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2352-7714 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8779  
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Author Philippe Ricaud, Massimo Del Guasta, Angelo Lupi, Romain Roehrig, Eric Bazile, Pierre Durand, Jean-Luc Attié, Alessia Nicosia, Paolo Grigioni doi  openurl
  Title Supercooled liquid water clouds observed over Dome C, Antarctica: temperature sensitivity and cloud radiative forcing Type Journal
  Year (down) 2024 Publication Atmospheric Chemistry and Physics Abbreviated Journal  
  Volume 24 Issue 1 Pages 613-630  
  Keywords  
  Abstract Clouds affect the Earth climate with an impact that depends on the cloud nature (solid and/or liquid water). Although the Antarctic climate is changing rapidly, cloud observations are sparse over Antarctica due to few ground stations and satellite observations. The Concordia station is located on the eastern Antarctic Plateau (75∘ S, 123∘ E; 3233 m above mean sea level), one of the driest and coldest places on Earth. We used observations of clouds, temperature, liquid water, and surface irradiance performed at Concordia during four austral summers (December 2018–2021) to analyse the link between liquid water and temperature and its impact on surface irradiance in the presence of supercooled liquid water (liquid water for temperature less than 0 ∘C) clouds (SLWCs). Our analysis shows that, within SLWCs, temperature logarithmically increases from −36.0 to −16.0 ∘C when liquid water path increases from 1.0 to 14.0 g m−2. The SLWC radiative forcing is positive and logarithmically increases from 0.0 to 70.0 W m−2 when liquid water path increases from 1.2 to 3.5 g m−2. This is mainly due to the downward longwave component that logarithmically increases from 0 to 90 W m−2 when liquid water path increases from 1.0 to 3.5 g m−2. The attenuation of shortwave incoming irradiance (that can reach more than 100 W m−2) is almost compensated for by the upward shortwave irradiance because of high values of surface albedo. Based on our study, we can extrapolate that, over the Antarctic continent, SLWCs have a maximum radiative forcing that is rather weak over the eastern Antarctic Plateau (0 to 7 W m−2) but 3 to 5 times larger over West Antarctica (0 to 40 W m−2), maximizing in summer and over the Antarctic Peninsula.  
  Programme 910  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1680-7316 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8780  
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Author Sarah Leclaire, Maxime Pineaux, Pierrick Blanchard, Joël White, Scott A. Hatch doi  openurl
  Title Microbiota composition and diversity of multiple body sites vary according to reproductive performance in a seabird Type Journal
  Year (down) 2023 Publication Molecular Ecology Abbreviated Journal  
  Volume 32 Issue 9 Pages 2115-2133  
  Keywords bacteria black-legged kittiwake feathers fitness individual quality microbiota reproductive success  
  Abstract The microbiota is suggested to be a fundamental contributor to host reproduction and survival, but associations between microbiota and fitness are rare, especially for wild animals. Here, we tested the association between microbiota and two proxies of breeding performance in multiple body sites of the black-legged kittiwake, a seabird species. First we found that, in females, nonbreeders (i.e., birds that did not lay eggs) hosted different microbiota composition to that of breeders in neck and flank feathers, in the choanae, in the outer-bill and in the cloacae, but not in preen feathers and tracheae. These differences in microbiota might reflect variations in age or individual quality between breeders and nonbreeders. Second, we found that better female breeders (i.e., with higher body condition, earlier laying date, heavier eggs, larger clutch, and higher hatching success) had lower abundance of several Corynebacteriaceae in cloaca than poorer female breeders, suggesting that these bacteria might be pathogenic. Third, in females, better breeders had different microbiota composition and lower microbiota diversity in feathers, especially in preen feathers. They had also reduced dispersion in microbiota composition across body sites. These results might suggest that good breeding females are able to control their feather microbiota—potentially through preen secretions—more tightly than poor breeding females. We did not find strong evidence for an association between reproductive outcome and microbiota in males. Our results are consistent with the hypothesis that natural variation in the microbiota is associated with differences in host fitness in wild animals, but the causal relationships remain to be investigated.  
  Programme 1162  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1365-294X ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8391  
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Author Sophia Ferchiou, France Caza, Richard Villemur, Jacques Labonne, Yves St-Pierre doi  openurl
  Title Skin and Blood Microbial Signatures of Sedentary and Migratory Trout (Salmo trutta) of the Kerguelen Islands Type Journal
  Year (down) 2023 Publication Fishes Abbreviated Journal  
  Volume 8 Issue 4 Pages 174  
  Keywords Salmo trutta 16S rRNA blood microbiome fish Kerguelen Islands migration skin microbiome  
  Abstract Our understanding of how microbiome signatures are modulated in wild fish populations remains poorly developed and has, until now, mostly been inferred from studies in commercial and farmed fish populations. Here, for the first time, we have studied changes in the skin and blood microbiomes of the Salmo trutta population of the volcanic Kerguelen archipelago located at the northern limit of the Antarctic Ocean. The Kerguelen Islands present a natural framework of population expansion and reveal a likely situation representing further climate change in distribution areas. Our results showed that S. trutta of the Kerguelen Islands has a microbiome signature distinct from those of salmonids of the Northern Hemisphere. Our study also revealed that the skin and blood microbiomes differ between sedentary and migratory S. trutta. While 18 phyla were shared between both groups of trout, independent of the compartment, 6 phyla were unique to migratory trout. Further analyses showed that microbiome signatures undergo significant site-specific variations that correlate, in some cases, with the peculiarity of specific ecosystems. Our study also revealed the presence of potential pathogens at particular sites and the impact of abiotic factors on the microbiome, most notably due to the volcanic nature of the environment. This study contributes to a better understanding of the factors that modulate the microbiome signatures of migratory and sedentary fish populations. It will also help to better monitor the impacts of climate change on the colonization process in the sub-Antarctic region.  
  Programme 1041  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2410-3888 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8404  
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Author Karl-Ludwig Klein, Sophie Musset, Nicole Vilmer, Carine Briand, Säm Krucker, Andrea Francesco Battaglia, Nina Dresing, Christian Palmroos, Dale E. Gary doi  openurl
  Title The relativistic solar particle event on 28 October 2021: Evidence of particle acceleration within and escape from the solar corona Type Journal
  Year (down) 2023 Publication Astronomy & Astrophysics Abbreviated Journal  
  Volume 663 Issue Pages A173  
  Keywords  
  Abstract Aims. We analyse particle, radio, and X-ray observations during the first relativistic proton event of solar cycle 25 detected on Earth. The aim is to gain insight into the relationship between relativistic solar particles detected in space and the processes of acceleration and propagation in solar eruptive events.Methods. To this end, we used ground-based neutron monitor measurements of relativistic nucleons and space-borne measurements of electrons with similar speed to determine the arrival times of the first particles at 1 AU and to infer their solar release times. We compared the release times with the time histories of non-thermal electrons in the solar atmosphere and their escape to interplanetary space, as traced by radio spectra and X-ray light curves and images.Results. Non-thermal electrons in the corona are found to be accelerated in different regions. Some are confined in closed magnetic structures expanding during the course of the event. Three episodes of electron escape to the interplanetary space are revealed by groups of decametric-to-kilometric type III bursts. The first group appears on the low-frequency side of a type II burst produced by a coronal shock wave. The two latter groups are accompanied at higher frequencies by bursts with rapid drifts to both lower and higher frequencies (forward- or reverse-drifting bursts). They are produced by electron beams that propagate both sunward and anti-sunward. The first relativistic electrons and nucleons observed near Earth are released with the third group of type III bursts, more than ten minutes after the first signatures of non-thermal electrons and of the formation of the shock wave in the corona. Although the eruptive active region is near the central meridian, several tens of degrees east of the footpoint of the nominal Parker spiral to the Earth, the kilometric spectrum of the type III bursts and the in situ detection of Langmuir waves demonstrate a direct magnetic connection between the L1 Lagrange point and the field lines onto which the electron beams are released at the Sun.Conclusions. We interpret the forward- and reverse-drifting radio bursts as evidence of reconnection between the closed expanding magnetic structures of an erupting flux rope and ambient open magnetic field lines. We discuss the origin of relativistic particles near the Earth across two scenarios: (1) acceleration at the CME-driven shock as it intercepts interplanetary magnetic field lines rooted in the western solar hemisphere and (2) an alternative where the relativistic particles are initially confined in the erupting magnetic fields and get access to the open field lines to the Earth through these reconnection events.  
  Programme 227  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0004-6361, 1432-0746 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8441  
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Author Florent Tencé, Julien Jumelet, Marie Bouillon, David Cugnet, Slimane Bekki, Sarah Safieddine, Philippe Keckhut, Alain Sarkissian doi  openurl
  Title 14 years of lidar measurements of polar stratospheric clouds at the French Antarctic station Dumont d'Urville Type Journal
  Year (down) 2023 Publication Atmospheric chemistry and physics Abbreviated Journal  
  Volume 23 Issue 1 Pages 431-451  
  Keywords  
  Abstract

Abstract. Polar stratospheric clouds (PSCs) play a critical role in the stratospheric ozone depletion processes. The last 30 years have seen significant improvements in our understanding of the PSC processes but PSC parametrization in global models still remains a challenge due to the necessary trade-off between the complexity of PSC microphysics and model parametrization constraints. The French Antarctic station Dumont d'Urville (DDU, 66.6 S, 140.0 E) has one of the few high latitude ground-based lidars in the Southern Hemisphere that has been monitoring PSCs for decades. This study focuses on the PSC data record during the 2007–2020 period. First, the DDU lidar record is analysed through three established classification schemes that prove to be mutually consistent: the PSC population observed above DDU is estimated to be of 30 % supercooled ternary solutions, more than 60 % nitric acid trihydrate mixtures and less than 10 % of water–ice dominated PSC. The Cloud–Aerosol Lidar with Orthogonal Polarization PSC detection around the station are compared to DDU PSC datasets and show a good agreement despite more water–ice PSC detection. Detailed 2015 lidar measurements are presented to highlight interesting features of PSC fields above DDU. Then, combining a temperature proxy to lidar measurements, we build a trend of PSC days per year at DDU from ERA5 (the fifth generation of European ReAnalysis) and NCEP (National Centers for Environment Protection reanalysis) reanalyses fitted on lidar measurements operated at the station. This significant 14-year trend of 4.6 PSC days per decade is consistent with recent temperature satellite measurements at high latitudes. Specific DDU lidar measurements are presented to highlight fine PSC features that are often sub-scale to global models and spaceborne measurements.

 
  Programme 209  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1680-7316 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8491  
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