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Dartois E, Engrand C, Brunetto R, Duprat J, Pino T, Quirico E, Remusat L, Bardin N, Briani G, Mostefaoui S, Morinaud G, Crane B, Szwec N, Delauche L, Jamme F, Sandt Ch, Dumas P, . (2013). UltraCarbonaceous Antarctic micrometeorites, probing the Solar System beyond the nitrogen snow-line
. Icarus, 224(1), 243–252.
Abstract: The current Solar System architecture is aheritage of the protoplanetary disk that surrounded the young
Sun, 4.56 Gy ago. Primitive extraterrestr ial objects provide means to trace back the primordial composi-
tion and radial distribution of matter in this disk. Here, we present acombined micro-IR, Raman, chem-
ical and isotopic study of two ultracarbonaceous micrometeorites recovered from Antar ctica (UCAMMs).
This study reveals particles containing an unusually high nitrogen- and deuterium-rich organic matter
analogous to a polyaromatic hydrogenated carbon nitride, characterized by nitrogen concentration with
bulk atomic N/C ratios of 0.05 and 0.12 (locallyexceeding 0.15).We propose that such nitrogen-rich car-
bonaceous material can be formed by energetic irradiations of nitrogen-rich ices in very low temperature
regions of the Solar System. Such conditions are encountered at the surface of small objects beyond the
trans-neptunian region. UCAMMs provide unique insights on physico-chemical processes that occurred
beyond the nitrogen snow-line, revealing orga nic material from the extreme outer regions of the Solar
System that cannot be investigated by remote sensing methods.
Keywords: Origin, Solar System, Interplanetary dust, Cosmochemistry, Cosmic rays, Organic chemistry,
Programme: 1120
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Aude Villemain, Patrice Godon. (2017). Toward a resilient organization: The management of unexpected hazard on the polar traverse (Vol. 95).
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Spracklen, D.V.; Arnold, S.R.; Sciare, J.; Carslaw, K.S.; Pio, C. (2008). Globally significant oceanic source of organic carbon aerosol. Geophysical research letters, 35.
Keywords: organic carbon; ocean; aerosol; 0305 Atmospheric Composition and Structure: Aerosols and particles; 0315 Atmospheric Composition and Structure: Biosphere/atmosphere interactions; 0312 Atmospheric Composition and Structure: Air/sea constituent fluxes
Programme: 414;415
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Sciare J, Favez O, Sarda-Estve R, Oikonomou K, Cachier H, Kazan V, . (2009). Long-term observations of carbonaceous aerosols in the Austral Ocean atmosphere: Evidence of a biogenic marine organic source
. J. Geophys. Res., 114(D15), D15302–.
Keywords: organic aerosols, black carbon, biogenic aerosols, Austral Ocean, chlorophyll a, 0305 Atmospheric Composition and Structure: Aerosols and particles, 0365 Atmospheric Composition and Structure: Troposphere: composition and chemistry, 3339 Atmospheric Processes: Ocean/atmosphere interactions,
Programme: 414;415;416
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Caro Samuel P, Balthazart Jacques, Bonadonna Francesco, . (2015). The perfume of reproduction in birds: Chemosignaling in avian social life
. Hormones and Behavior, 68, 25–42.
Abstract: Chemical cues were probably the first cues ever used to communicate and are still ubiquitous among living organisms. Birds have long been considered an exception: it was believed that birds were anosmic and relied on their acute visual and acoustic capabilities. Birds are however excellent smellers and use odors in various contexts including food searching, orientation, and also breeding. Successful reproduction in most vertebrates involves the exchange of complex social signals between partners. The first evidence for a role of olfaction in reproductive contexts in birds only dates back to the seventies, when ducks were shown to require a functional sense of smell to express normal sexual behaviors. Nowadays, even if the interest for olfaction in birds has largely increased, the role that bodily odors play in reproduction still remains largely understudied. The few available studies suggest that olfaction is involved in many reproductive stages. Odors have been shown to influence the choice and synchronization of partners, the choice of nest-buildingmaterial or the care for the eggs and offspring. How this chemical information is translated at the physiological level mostly remains to be described, although available evidence suggests that, as in mammals, key reproductive brain areas like the medial preoptic nucleus are activated by relevant olfactory signals. Olfaction in birds receives increasing attention and novel findings are continuously published, but many exciting discoveries are still ahead of us, and could make birds one of the animal classes with the largest panel of developed senses ever described.
Keywords: Olfaction, Pheromone, Avian, Sexual selection recognition,
Programme: 354
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Homberg, C.; Bergerat, F.; Angelier, J.; Garcia, S. (2010). Fault interaction and stresses along broad oceanic transform zone: Tjrnes Fracture Zone, north Iceland. Tectonics, 29(1), TC1002.
Abstract: Transform motion along oceanic transforms generally occurs along narrow faults zones. Another class of oceanic transforms exists where the plate boundary is quite large (?100 km) and includes several subparallel faults. Using a 2-D numerical modeling, we simulate the slip distribution and the crustal stress field geometry within such broad oceanic transforms (BOTs). We examine the possible configurations and evolution of such BOTs, where the plate boundary includes one, two, or three faults. Our experiments show that at any time during the development of the plate boundary, the plate motion is not distributed along each of the plate boundary faults but mainly occurs along a single master fault. The finite width of a BOT results from slip transfer through time with locking of early faults, not from a permanent distribution of deformation over a wide area. Because of fault interaction, the stress field geometry within the BOTs is more complex than that along classical oceanic transforms and includes stress deflections close to but also away from the major faults. Application of this modeling to the 100 km wide Tjrnes Fracture Zone (TFZ) in North Iceland, a major BOT of the Mid-Atlantic Ridge that includes three main faults, suggests that the Dalvik Fault and the Husavik-Flatey Fault developed first, the Grismsey Fault being the latest active structure. Since initiation of the TFZ, the Husavik-Flatey Fault accommodated most of the plate motion and probably persists until now as the main plate structure.
Keywords: oceanic transform; fault interaction; stresses; Iceland; slip transfer; 8150 Tectonophysics: Plate boundary: general; 8164 Tectonophysics: Stresses: crust and lithosphere; 8020 Structural Geology: Mechanics, theory, and modeling
Programme: 316
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Pontier Dominique, Fouchet David, Bried Jol, . (2010). Can cat predation help competitors coexist in seabird communities?
. J. Theor. Biol., 262(1), 90–96.
Abstract: On oceanic islands, nest site availability can be an important factor regulating seabird population dynamics. The potential for birds to secure a nest to reproduce can be an important component of their life histories. The dates at which different seabird species arrive at colonies to breed will have important consequences for their relative chances of success. Early arrival on the island allows birds to obtain nests more easily and have higher reproductive success. However, the presence of an introduced predator may reverse this situation. For instance, in the sub-Antarctic Kerguelen archipelago, early arriving birds suffer heavy predation from introduced cats. Cats progressively switch from seabirds to rabbits, since the local rabbit population starts to peak after early arriving seabird species have already returned to the colony. When late-arriving birds arrive, cat predation pressure on seabirds is thus weaker. In this paper, we investigate the assumption that the advantage of early nest mnopolization conferred to early arriving birds may be counterbalanced by the cost resulting from predation. We develop a mathematical model representing a simplified situation in which two insular seabird species differ only in their arrival date at the colony site and compete for nesting sites. We conclude that predation may ensure the coexistence of the two bird species or favor the late-arriving species, but only when seasonal variations in predation pressure are large. Interestingly, we conclude that arriving early is only favorable until a given level where high reproductive success no longer compensates for the long exposure to strong predation pressure. Our work suggests that predation can help to maintain the balance between species of different phenologies.
Keywords: Oceanic islands, Seabirds, Feral cats, Nest site availability, Date of arrival, Community structure, Predator-prey relationships, Model,
Programme: 279
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Beine Harry, Anastasio Cort, Domine Florent, Douglas Thomas, Barret Manuel, France James, King Martin, Hall Sam, Ullmann Kirk, . (2012). Soluble chromophores in marine snow, seawater, sea ice and frost flowers near Barrow, Alaska
. J. Geophys. Res., 117, D00R15–.
Keywords: OASIS, chromophores, colored dissolved organic matter (CDOM), frost flowers, light absorption, marine, 0317 Atmospheric Composition and Structure: Chemical kinetic and photochemical properties, 0322 Atmospheric Composition and Structure: Constituent sources and sinks, 0736 Cryosphere: Snow (1827, 1863), 0750 Cryosphere: Sea ice (4540), 4807 Oceanography: Biological and Chemical: Chemical speciation and complexation,
Programme: 1017
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. (2023). (Vol. 55).
Keywords: Nunavik snow avalanches Time-lapse cameras weather data
Programme: 1148
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A. Jamelot, A. Gailler, Ph. Heinrich, A. Vallage, J. Champenois. (2019). Tsunami Simulations of the Sulawesi Mw 7.5 Event: Comparison of Seismic Sources Issued from a Tsunami Warning Context Versus Post-Event Finite Source (Vol. 176).
Abstract: The 28 September 2018 Sulawesi earthquake generated a much larger tsunami than expected from its Mw = 7.5 magnitude and from its dominant strike-slip mechanism. Within a few minutes after the earthquake, the tsunami devastated the seafront of Palu bay, destroying houses and infrastructures over a few hundred meters. Coastal subsidence and slumping at various locations around the bay were also observed. There is debate in the scientific community as to whether submarine landslides and shore collapses contributed to the generation of strong and destructive waves locally. The objective of this study is threefold: first, to determine whether standard seismic inversions could predict the source in the context of tsunami early warning; second, to define a new seismic source built from optical image correlation and based on the geological and tectonic context; third, to assess whether the earthquake alone is able to generate up to 9-m wave heights at the coast. Numerical simulations of the tsunami propagation are performed for different seismic dislocation sources. Nonlinear shallow water equations are solved by a finite-difference method in grids with 200-m and 10-m resolutions. The early CMT focal solutions calculated by seismological institutes show dominant strike-slip mechanisms with a homogenous slip distribution. These sources produce maximum tsunami heights of 40-cm on the coast of Palu city. Two heterogeneous sources are tested and compared: the USGS “finite fault” model calculated from seismic inversion and a new “hybrid” source inferred from different techniques. The latter is based on a segmented fault in agreement with the geological context and built from both from seismic parameters of a CMT solution and the observed horizontal ground displacements. This source produces water wave heights of 4 to 5-m in the Palu bay. The observed inundation heights and distances are reproduced satisfactorily by the model at Pantoloan and at the southwestern tip of Palu bay. However, the “hybrid” source is unable to reproduce the largest 8 to 12-m water heights as reported from field surveys. Thus, even though this “hybrid” source produces most of the reported tsunami energy, we cannot exclude that the numerous coastal collapses observed in Palu bay contributed to increase the local tsunami run-up.
Keywords: numerical modelling strike-slip Sulawesi supershear Tsunami
Programme: 133
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