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Dorothée Ehrich, Niels M. Schmidt, Gilles Gauthier, Ray Alisauskas, Anders Angerbjörn, Karin Clark, Frauke Ecke, Nina E. Eide, Erik Framstad, Jay Frandsen, Alastair Franke, Olivier Gilg, Marie-Andrée Giroux, Heikki Henttonen, Birger Hörnfeldt, Rolf A. Ims, Gennadiy D. Kataev, Sergey P. Kharitonov, Siw T. Killengreen, Charles J. Krebs, Richard B. Lanctot, Nicolas Lecomte, Irina E. Menyushina, Douglas W. Morris, Guy Morrisson, Lauri Oksanen, Tarja Oksanen, Johan Olofsson, Ivan G. Pokrovsky, Igor Yu. Popov, Donald Reid, James D. Roth, Sarah T. Saalfeld, Gustaf Samelius, Benoit Sittler, Sergey M. Sleptsov, Paul A. Smith, Aleksandr A. Sokolov, Natalya A. Sokolova, Mikhail Y. Soloviev, Diana V. Solovyeva. (2020). Documenting lemming population change in the Arctic: Can we detect trends? (Vol. 49).
Abstract: Lemmings are a key component of tundra food webs and changes in their dynamics can affect the whole ecosystem. We present a comprehensive overview of lemming monitoring and research activities, and assess recent trends in lemming abundance across the circumpolar Arctic. Since 2000, lemmings have been monitored at 49 sites of which 38 are still active. The sites were not evenly distributed with notably Russia and high Arctic Canada underrepresented. Abundance was monitored at all sites, but methods and levels of precision varied greatly. Other important attributes such as health, genetic diversity and potential drivers of population change, were often not monitored. There was no evidence that lemming populations were decreasing in general, although a negative trend was detected for low arctic populations sympatric with voles. To keep the pace of arctic change, we recommend maintaining long-term programmes while harmonizing methods, improving spatial coverage and integrating an ecosystem perspective.
Programme: 1036
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Fabienne Joliet, Véronique Van Tilbeurgh, Anne Atlan. (2020). La valeur d’existence du monde vivant selon les Inuits du Nunavik et les Occidentaux aux Kerguelen (Vol. 732).
Abstract: Dans le contexte actuel de transition socio-écologique internationale, l’objectif de cet article est d’interroger la relation entre les humains et les autres vivants et choses naturelles dans les derniers espaces de vaste naturalité aux pôles. C’est à travers la notion de valeur d’existence que cette relation sera analysée dans ses retranchements chez les Inuits qui habitent le Nunavik en subarctique et les Occidentaux qui veillent sur les Kerguelen en subantarctique. Plus particulièrement, c’est la nature du lien qu’ils entretiennent avec les vivants non-humains et autres choses naturelles, et ses registres de valeurs qui sont étudiées.Ces enquêtes boréales et australes en zone protégée ou bien à ses abords montrent ainsi que ce qui prédomine, c’est le fait qu’il est attribué aux éléments naturels une valeur d’existence en fonction d’un esprit commun spirituel ou bien d’une enveloppe commune charnelle d’« être vivant ». Selon ces principes, les modalités prises par l’attribution de la valeur d’existence changent : les humains se concevant soit, comme une partie d’un ensemble au même titre que les autres vivants et choses naturelles ayant un esprit ou conscience, soit comme maîtres et protecteurs des autres vivants et choses naturelles, en tant qu’ayant une fonction dominante au sein d’« êtres vivants ». Dans cette perspective, le territoire joue un rôle spécifique favorisant l’existence même de cette valeur au-delà de ses fonctions de régulation couramment retenues.
Programme: 136
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Christophe Barbraud, Adrien Chaigne, Maxime Loubon, Olivier Lamy, Fabrice Le Bouard. (2020). An estimate of the South Georgia diving petrel Pelecanoides georgicus population at Ile de la Possession, Crozet archipelago (Vol. 32).
Abstract: Burrow-nesting seabirds constitute an important part of seabird diversity, yet accurate estimates of their abundance are largely lacking, limiting our understanding of their population dynamics and conservation status. We conducted a survey to estimate the number of South Georgia diving petrel (Pelecanoides georgicus) burrows during the 2013–14 breeding season on Ile de la Possession, Crozet archipelago, southern Indian Ocean. We used distance sampling and acoustic playback in order to estimate burrow densities in a priori-selected favourable nesting areas. A total of 855 burrows were detected. The mean altitude of burrows was 601.8 ± 69.4 m. The mean burrow detection distance was 1.77 ± 1.63 m. The burrow density was estimated at 15.649 burrows ha-1 (95% confidence interval (CI): 10.245–23.903) and the slope-corrected total favourable area was 2365.53 ha, which yielded an estimate 37 018 burrows (95% CI: 24 235–56 544). The playback response rate was 15.8 ± 1.3%, and 40.8 ± 1.7% of burrows were occupied or showed signs of occupation. Occupancy rates were low compared to those measured by systematic burrow inspection in other studies. Assuming that laying occurred in 80–93% of the estimated number of burrows, as estimated by previous studies, gives an estimate of 29 614 (95% CI: 19 388–45 235) to 34 426 (95% CI: 22 538–52 585) breeding pairs.
Keywords: acoustic playback burrowing petrel detection probability distance sampling Procellariiformes
Programme: 109
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Encelyn Voisine, Yann Rolland, Matthias Bernet, Julien Carcaillet, Guillaume Duclaux, Jérôme Bascou, Christian Sue, Mélanie Balvay, René-Pierre Ménot. (2020). Antarctic erosion history reconstructed by Terre Adélie moraine geochronology.
Abstract: We report apatite fission-track and 10Be terrestrial cosmogenic nuclide (TCN) dating of 14 moraine boulders originating from inland Terre Adélie, East Antarctica. These data show cooling of the Proterozoic Terre Adélie craton at < ~120°C between 350 and 300 Ma, suggesting > 4 km temperate glacial erosion during the Late Palaeozoic Ice Age, followed by nearly null Mesozoic erosion and low glacial erosion (< 2 km) in the Cenozoic. Based on glacial flux maps, the origin of the boulders may be located ~400 km upstream. Preliminary TCN (10Be) datings of moraine boulders cluster within the last 30 ka. Cosmogenic ages from the Lacroix Nunatak suggest a main deglaciation after the Younger Dryas at c. 10 ka, while those of Cap Prud'homme mostly cluster at 0.6 ka, in agreement with an exhumation of boulders during the Little Ice Age.
Keywords: cosmogenic nuclide dating deglaciation exhumation fission-track dating Late Palaeozoic Ice Age subglacial incision
Programme: 1003
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Philippe Ricaud, Paolo Grigioni, Romain Roehrig, Pierre Durand, Dana E. Veron. (2020). Trends in Atmospheric Humidity and Temperature above Dome C.
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Ricaud, P., Del Guasta M., Bazile E., Azouz N., Lupi A., Durand P., Attié J.-L., Veron D., Guidard V., Grigioni P. (2020). Supercooled Liquid Water Cloud observed, analysed and modelled at the Top of the Planetary Boundary Layer above Dome C.
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David Boertmann, Flemming Merkel, Olivier Gilg. (2020). Seabird Breeding Colonies in East and North Greenland: A Baseline (Vol. 73).
Abstract: This paper presents the results of a number of aircraft- and boat-based surveys for seabird breeding colonies in East and North Greenland carried out in the period 2003 to 2018 and gives the first comprehensive overview of the distribution and size of the seabird breeding colonies in this remote and mainly uninhabited region. Seventeen seabird species breed in approximately 800 sites distributed very unevenly along the coasts, with high concentrations at the polynyas and long stretches with very few breeding seabirds. Climate changes are in full progress in East and North Greenland, especially affecting the sea ice regime, and seabirds are expected to respond to these changes in different ways. For example, since the 1980s, Common Eiders (Somateria mollissima) have extended their breeding range more than two latitudinal degrees towards the north, now reaching the northernmost land on Earth. Lesser Black-backed Gulls (Larus fuscus) and Great Cormorants (Phalacrocorax carbo) have immigrated, and Sabine’s Gulls (Xema sabini) have increased and extended their range. Besides presenting survey results, this report may also serve as a baseline for future studies of the abundance of breeding seabirds in East and North Greenland.
Keywords: climate change colonial seabirds distribution Greenland
Programme: 1036
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Alexandra Lavrillier. (2020). “Spirit-Charged” Humans in Siberia: Interrelations between the Notions of the Individual (“Spirit Charge” and “Active Imprint”) and (Ritual) Action (Vol. 57).
Abstract: This paper shows how a society imagines human individuals and their power to act upon spirits both ritually and materially. Based on the author’s fieldwork (from 1994 to 2019), it analyzes the emic concept onnir, which is omnipresent in the daily activities and the past and present collective/individual rituals of Siberian Evenki and Even. Each human owns a specific fluctuating “charge made of spirits” and an “active imprint” that empowers the human to act, perform rituals, develop talents, and create. Even after death, this “imprint” affects everything and everyone a human ever touched. Onnir defines the interrelations between the individual, the spirits of his or her own “charge,” and the spirits of the universe in an “active agent”-“patient” relationship. This paper contributes to studies of the notions of the individual, “playing” as a ritual means, the acceptance/rejection of neoshamans, neorituals, and the (ritual) agency of ordinary individuals.
Programme: 1127
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Fabrizio Magrini, Dario Jozinović, Fabio Cammarano, Alberto Michelini, Lapo Boschi. (2020). Local earthquakes detection: A benchmark dataset of 3-component seismograms built on a global scale (Vol. 1).
Abstract: Machine learning is becoming increasingly important in scientific and technological progress, due to its ability to create models that describe complex data and generalize well. The wealth of publicly-available seismic data nowadays requires automated, fast, and reliable tools to carry out a multitude of tasks, such as the detection of small, local earthquakes in areas characterized by sparsity of receivers. A similar application of machine learning, however, should be built on a large amount of labeled seismograms, which is neither immediate to obtain nor to compile. In this study we present a large dataset of seismograms recorded along the vertical, north, and east components of 1487 broad-band or very broad-band receivers distributed worldwide; this includes 629,095 3-component seismograms generated by 304,878 local earthquakes and labeled as EQ, and 615,847 ones labeled as noise (AN). Application of machine learning to this dataset shows that a simple Convolutional Neural Network of 67,939 parameters allows discriminating between earthquakes and noise single-station recordings, even if applied in regions not represented in the training set. Achieving an accuracy of 96.7, 95.3, and 93.2% on training, validation, and test set, respectively, we prove that the large variety of geological and tectonic settings covered by our data supports the generalization capabilities of the algorithm, and makes it applicable to real-time detection of local events. We make the database publicly available, intending to provide the seismological and broader scientific community with a benchmark for time-series to be used as a testing ground in signal processing.
Keywords: Benchmark dataset Earthquake detection algorithm Seismology Supervised machine learning
Programme: 133
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Lebouvier Marc. (2020). Retour d'expérience sur l'éradication des ongulés introduits dans les îles subantarctiques. Bachelor's thesis, , .
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