| Records |
| Author |
Meagan Dewar, Michelle Wille, Amandine Gamble, Ralph Vanstreels, Thierry Boulinier, Adrian Smith, Arvind Varsani, Norman Ratcliffe, Jennifer Black, Amanda Lynnes |
| Title |
The Risk of Avian Influenza in the Southern Ocean: A practical guide |
Type |
Journal |
| Year |
2022 |
Publication |
Ecoevorxiv preprints |
Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
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| Keywords |
Antarctica, Avian Influenza, Infectious disease, Seabirds, sub-Antarctic |
| Abstract |
Advice from Avian Influenza experts suggests that there is a high risk that Highly Pathogenic Avian Influenza will arrive in the Southern Ocean 2022/23-2024/25 austral summers. Since the beginning of 2022, the increasing intensity of highly pathogenic avian influenza (HPAI) H5N1 outbreaks has resulted in the death of hundreds of thousands of seabirds in the Northern Hemisphere, around the Atlantic and Pacific Oceans and southern Africa. The SCAR Antarctic Wildlife Health Working Group (AWHWG) is highly concerned about the likely arrival and subsequent impact HPAI H5N1 might have on Southern Ocean wildlife. Due to the heightened risk of HPAI being introduced to Antarctica during the the 2022/23 Austral summer by migrating seabirds, the AWHWG recommends that: People working with or close to wildlife should assume that HPAI will arrive in the sub-Antarctic and Antarctica and take precautions to protect themselves when working around wildlife (including appropriate PPE) and maintain the highest biosecurity to prevent transmission between wildlife aggregations. All National Programmes (NPs) and tourism operators should monitor colonies for signs of H5N1 before approaching, especially in migratory species such as skuas, gulls and giant petrels. Tourists should not enter colonies and high wildlife density areas with suspected HPAI and NPs should conduct risk analysis as to which activities need to continue. A more detailed protocol on how to assess wildlife aggregations for HPAI prior to a visit and what to do if HPAI is detected should be provided to all stakeholders physically present in Antarctica this season. If you detect signs of HPAI, you should report this to your permit issuer. Videos of affected animals are very helpful for experts to help determine whether or not this is HPAI. Operators should refresh themselves with and review all biosecurity and any response guidelines to unusual/mass mortality events. This document aims to: Outline the likely risk to Southern Ocean taxa (a more technical assessment will follow in a separate document). Suggest which risks can be mitigated in light of human activity, transmission into and out of Antarctica and the sub-Antarctic regions through all operators as well as movements between sites within the Southern Ocean (primarily for science and tourism), Start discussion with National Programmes about ongoing monitoring for disease and consequences. |
| Programme |
1151 |
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ISBN |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
8758 |
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| Author |
Elena Dobrică, Ryan C. Ogliore, Cécile Engrand, Kazuhide Nagashima, Adrian J. Brearley |
| Title |
Mineralogy and oxygen isotope systematics of magnetite grains and a magnetite-dolomite assemblage in hydrated fine-grained Antarctic micrometeorites |
Type |
Journal |
| Year |
2019 |
Publication |
Meteoritics & Planetary Science |
Abbreviated Journal |
|
| Volume |
54 |
Issue |
9 |
Pages |
1973-1989 |
| Keywords |
|
| Abstract |
We report the mineralogy and texture of magnetite grains, a magnetite-dolomite assemblage, and the adjacent mineral phases in five hydrated fine-grained Antarctic micrometeorites (H-FgMMs). Additionally, we measured the oxygen isotopic composition of magnetite grains and a magnetite-dolomite assemblage in these samples. Our mineralogical study shows that the secondary phases identified in H-FgMMs have similar textures and chemical compositions to those described previously in other primitive solar system materials, such as carbonaceous chondrites. However, the oxygen isotopic compositions of magnetite in H-FgMMs span a range of ∆17O values from +1.3‰ to +4.2‰, which is intermediate between magnetites measured in carbonaceous and ordinary chondrites (CCs and OCs). The δ18O values of magnetites in one H-FgMM have a 27‰ mass-dependent spread in a single 100 × 200 μm particle, indicating that there was a localized control of the fluid composition, probably due to a low water-to-rock mass ratio. The ∆17O values of magnetite indicate that H-FgMMs sampled a different aqueous fluid than ordinary and carbonaceous chondrites, implying that the source of H-FgMMs is probably distinct from the asteroidal source of CCs and OCs. Additionally, we analyzed the oxygen isotopic composition of a magnetite-dolomite assemblage in one of the H-FgMMs (sample 03-36-46) to investigate the temperature at which these minerals coprecipitated. We have used the oxygen isotope fractionation between the coexisting magnetite and dolomite to infer a precipitation temperature between 160 and 280 °C for this sample. This alteration temperature is 100–200 °C warmer than that determined from a calcite-magnetite assemblage from the CR2 chondrite Al Rais, but similar to the estimated temperature of aqueous alteration for unequilibrated OCs, CIs, and CMs. This suggests that the sample 03-36-46 could come from a parent body that was large enough to attain temperatures as high as the OCs, CIs, and CMs, which implies an asteroidal origin for this particular H-FgMM. |
| Programme |
1120 |
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| ISSN |
1945-5100 |
ISBN |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
7898 |
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| Author |
Memin, A., Et Al. |
| Title |
Secular gravity variation at Svalbard (Norway) from ground observations and GRACE satellite data |
Type |
Journal |
| Year |
2011 |
Publication |
Geophysical journal international |
Abbreviated Journal |
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| Volume |
184 |
Issue |
3 |
Pages |
1119-1130 |
| Keywords |
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| Abstract |
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| Programme |
337 |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
7629 |
| Permanent link to this record |
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| Author |
Audrey Jaeger, Amandine Gamble, Erwan Lagadec, Camille Lebarbenchon, Vincent Bourret, Jérémy Tornos, Christophe Barbraud, Karin Lemberger, Karine Delord, Henri Weimerskirch, Jean-Baptiste Thiebot, Thierry Boulinier, Pablo Tortosa |
| Title |
Exploring the infection dynamics of a bacterial pathogen on a remote oceanic island reveals annual epizootics impacting an albatross population |
Type |
Journal |
| Year |
2019 |
Publication |
Biorxiv |
Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
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| Keywords |
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| Abstract |
Oceanic islands with reduced species richness provide an opportunity to investigate the emergence, maintenance and transmission of infectious diseases threatening wildlife. On Amsterdam Island, in the southern Indian Ocean, massive and recurrent mortality of the nestlings of Indian yellow-nosed albatross (Thalassarche carteri) has been attributed to avian cholera caused by Pasteurella multocida, a bacterial pathogen of likely human introduction. To understand the annual dynamics of pathogen prevalence, we measured the shedding of bacterial DNA by the albatrosses during four successive breeding seasons. The screening of 583 bird swabs by Real-Time PCR revealed an intense circulation of P. multocida during each study year, with a steady increase of infection prevalence across the breeding season. In the three years of highest pathogen prevalence, the epizootics were associated with massive die-offs of nestlings, inducing low annual fledging success (< 20%). These findings and developed PCR protocol have crucial applications for refining wildlife conservation plans aiming at controlling this disease. |
| Programme |
109 |
| Campaign |
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Place of Publication |
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ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
8360 |
| Permanent link to this record |
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| Author |
F. Pitout, A. Marchaudon, K. J. Trattner, J. Berchem, H. Laakso, C. P. Escoubet |
| Title |
Simultaneous Polar and Cluster Observations in the Northern and Southern Middle-Altitude Polar Cusps Around Equinox |
Type |
Journal |
| Year |
2020 |
Publication |
Journal of Geophysical Research: Space Physics |
Abbreviated Journal |
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| Volume |
125 |
Issue |
12 |
Pages |
e2020JA028346 |
| Keywords |
dayside magnetosphere hemispheric asymmetry polar cusp |
| Abstract |
We present an event of simultaneous observations of the northern and southern middle-altitude polar cusps by the Polar spacecraft and Cluster fleet that occurred on 23 September 2004. We examine the possible asymmetries in the fields and plasma parameters, although the proximity of the equinox should limit these asymmetries. Ion sensors reveal two dispersions in both cusps, and data analysis leads to the conclusion that those dispersions are due to pulsed reconnection at a single X-line, which runs along the subsolar magnetopause. While the electromagnetic and particle energy fluxes injected in both cusp are globally very similar, we report significant differences in ion dispersions, width of the low-latitude boundary layer, and peak convection velocities. We ascribe these differences to the dipole tilt that introduces an asymmetry in the magnetosheath flow at the exterior cusps. |
| Programme |
312 |
| Campaign |
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Place of Publication |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2169-9402 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
6363 |
| Permanent link to this record |
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| Author |
Weisen Shen, Douglas A. Wiens, Andrew J. Lloyd, Andrew A. Nyblade |
| Title |
A Geothermal Heat Flux Map of Antarctica Empirically Constrained by Seismic Structure |
Type |
Journal |
| Year |
2020 |
Publication |
Geophysical Research Letters |
Abbreviated Journal |
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| Volume |
47 |
Issue |
14 |
Pages |
e2020GL086955 |
| Keywords |
Antarctica crust and uppermost mantle geothermal heat flux ice sheet modeling |
| Abstract |
The geothermal heat flux (GHF) is an important boundary condition for modeling the movement of the Antarctic ice sheet but is difficult to measure systematically at a continental scale. Earlier GHF maps suffer from low resolution and possibly biased assumptions in tectonism and crustal heat generation, resulting in significant uncertainty. We present a new GHF map for Antarctica constructed by empirically relating the upper mantle structure to known GHF in the continental United States. The new map, compared with previously seismologically determined one, has improved resolution and lower uncertainties. New features in this map include high GHF in the southern Transantarctic Mountains where warmer uppermost mantle is introduced by lithospheric removal and in the Thwaites Glacier region. Additionally, a modest GHF in the central West Antarctic Rift system near the Siple Coast and an absence of large-scale regions with GHF greater than 90 mW/m2 are found. |
| Programme |
133 |
| Campaign |
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Thesis |
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Place of Publication |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1944-8007 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
7887 |
| Permanent link to this record |
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| Author |
Alison Ming, V. Holly L. Winton, James Keeble, Nathan L. Abraham, Mohit C. Dalvi, Paul Griffiths, Nicolas Caillon, Anna E. Jones, Robert Mulvaney, Joël Savarino, Markus M. Frey, Xin Yang |
| Title |
Stratospheric Ozone Changes From Explosive Tropical Volcanoes: Modeling and Ice Core Constraints |
Type |
Journal |
| Year |
2020 |
Publication |
Journal of geophysical research: atmospheres |
Abbreviated Journal |
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| Volume |
125 |
Issue |
11 |
Pages |
e2019JD032290 |
| Keywords |
Antarctica chemistry-climate modeling isotopes in ice cores ozone Samalas volcanic eruption |
| Abstract |
Major tropical volcanic eruptions have emitted large quantities of stratospheric sulfate and are potential sources of stratospheric chlorine although this is less well constrained by observations. This study combines model and ice core analysis to investigate past changes in total column ozone. Historic eruptions are good analogs for future eruptions as stratospheric chlorine levels have been decreasing since the year 2000. We perturb the preindustrial atmosphere of a chemistry-climate model with high and low emissions of sulfate and chlorine. The sign of the resulting Antarctic ozone change is highly sensitive to the background stratospheric chlorine loading. In the first year, the response is dynamical, with ozone increases over Antarctica. In the high HCl (2 Tg emission) experiment, the injected chlorine is slowly transported to the polar regions with subsequent chemical ozone depletion. These model results are then compared to measurements of the stable nitrogen isotopic ratio, , from a low snow accumulation Antarctic ice core from Dronning Maud Land (recovered in 2016–2017). We expect ozone depletion to lead to increased surface ultraviolet (UV) radiation, enhanced air-snow nitrate photochemistry and enrichment in in the ice core. We focus on the possible ozone depletion event that followed the largest volcanic eruption in the past 1,000 years, Samalas in 1257. The characteristic sulfate signal from this volcano is present in the ice core but the variability in dominates any signal arising from changes in ultraviolet from ozone depletion. Prolonged complete ozone removal following this eruption is unlikely to have occurred over Antarctica. |
| Programme |
1177 |
| Campaign |
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Place of Publication |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
2169-8996 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
7856 |
| Permanent link to this record |
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| Author |
Korbinian Sager, Christian Boehm, Laura Ermert, Lion Krischer, Andreas Fichtner |
| Title |
Global-Scale Full-Waveform Ambient Noise Inversion |
Type |
Journal |
| Year |
2020 |
Publication |
Journal of Geophysical Research: Solid Earth |
Abbreviated Journal |
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| Volume |
125 |
Issue |
4 |
Pages |
e2019JB018644 |
| Keywords |
computational seismology full-waveform inversion global tomography interferometry seismic noise |
| Abstract |
We present the first application of full-waveform ambient noise inversion to observed correlation functions that jointly constrains 3-D Earth structure and heterogeneous noise sources. For this, we model and interpret ambient noise correlations as recordings of correlation wavefields, which completely eliminates the limiting assumptions of Green's function retrieval, such as equipartitioning and homogeneous random noise sources. Our method accounts for seismic wave propagation physics in 3-D heterogeneous and attenuating media and also for the heterogeneous and nonstationary nature of the ambient noise field. Designed as a proof of concept, the study considers long periods from 100 to 300 s, thus focusing on the Earth's hum. Treating correlations as self-consistent observables allows us to make separate measurements on the causal and acausal branches of correlation functions, without any need to choose one of them or form the average. We validate our approach by assessing the quality of the obtained models and by comparing them to previous studies. This work is a step toward the establishment of full-waveform ambient noise inversion as a tomographic technique with the goal to go beyond ambient noise tomography based on Green's function retrieval. |
| Programme |
133 |
| Campaign |
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Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2169-9356 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
7794 |
| Permanent link to this record |
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| Author |
Weisen Shen, Douglas A. Wiens, Sridhar Anandakrishnan, Richard C. Aster, Peter Gerstoft, Peter D. Bromirski, Samantha E. Hansen, Ian W. D. Dalziel, David S. Heeszel, Audrey D. Huerta, Andrew A. Nyblade, Ralph Stephen, Terry J. Wilson, J. Paul Winberry |
| Title |
The Crust and Upper Mantle Structure of Central and West Antarctica From Bayesian Inversion of Rayleigh Wave and Receiver Functions |
Type |
Journal |
| Year |
2018 |
Publication |
Journal of Geophysical Research: Solid Earth |
Abbreviated Journal |
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| Volume |
123 |
Issue |
9 |
Pages |
7824-7849 |
| Keywords |
ambient noise tomography Antarctica crust and uppermost mantle Gamburtsev Mountains seismology Transantarctic Mountains |
| Abstract |
We construct a new seismic model for central and West Antarctica by jointly inverting Rayleigh wave phase and group velocities along with P wave receiver functions. Ambient noise tomography exploiting data from more than 200 seismic stations deployed over the past 18 years is used to construct Rayleigh wave phase and group velocity dispersion maps. Comparison between the ambient noise phase velocity maps with those constructed using teleseismic earthquakes confirms the accuracy of both results. These maps, together with P receiver function waveforms, are used to construct a new 3-D shear velocity (Vs) model for the crust and uppermost mantle using a Bayesian Monte Carlo algorithm. The new 3-D seismic model shows the dichotomy of the tectonically active West Antarctica (WANT) and the stable and ancient East Antarctica (EANT). In WANT, the model exhibits a slow uppermost mantle along the Transantarctic Mountains (TAMs) front, interpreted as the thermal effect from Cenozoic rifting. Beneath the southern TAMs, the slow uppermost mantle extends horizontally beneath the traditionally recognized EANT, hypothesized to be associated with lithospheric delamination. Thin crust and lithosphere observed along the Amundsen Sea coast and extending into the interior suggest involvement of these areas in Cenozoic rifting. EANT, with its relatively thick and cold crust and lithosphere marked by high Vs, displays a slower Vs anomaly beneath the Gamburtsev Subglacial Mountains in the uppermost mantle, which we hypothesize may be the signature of a compositionally anomalous body, perhaps remnant from a continental collision. |
| Programme |
133 |
| Campaign |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
2169-9356 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
7878 |
| Permanent link to this record |
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| Author |
O. P. Mishra |
| Title |
Seismo-Geophysical Studies in the Antarctic Region: Geodynamical Implications |
Type |
Journal |
| Year |
2022 |
Publication |
Assessing the Antarctic Environment from a Climate Change Perspective: An Integrated Approach |
Abbreviated Journal |
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| Volume |
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Issue |
|
Pages |
287-341 |
| Keywords |
Geodynamics Glacial dynamics GMCIE Plate reconstruction Seismic potential Seismo-geophysical structures Seismogenesis The Antarctic WARS |
| Abstract |
Conduction of integrated seismo-geophysical studies in the Antarctic region is a challenge as well as very much warranted to explore the region for its better geo-scientific understanding. Seismogenesis and seismic potential of the Antarctic region have not yet been well understood because of lack of common consensus on various issues, besides its unique and complex geotectonic settings associated with intriguing landscape evolution of the Antarctic plate since the breakup of Gondwana, West Antarctic Rift System (WARS), different patterns of exhumation events that occurred between the Early Cretaceous and Cenozoic. The hostile climatic situation and inaccessibility of the region due to the huge spatial distribution of thicker ice sheets hindered the mission of conducting comprehensive seismo-geophysical studies for the Antarctic Peninsula due to severe constraints of installations of ground-based sophisticated seismo-geophysical equipments in the region. Several causative factors associated with natural and anthropogenic are found still enigmatic in the sense to unravel the fact how the genesis of earthquakes are related to the glacial-dynamics and glacial mass change-induced earthquakes (GMCIE). It has become important to decipher the role and contribution of the East and the West Antarctic microplates and West Antarctic rift systems (WARS) in seismogenesis using advanced methodologies of geosciences. Seismicity of the Antarctic continent region is confined to different tectonic blocks, distributed into the southern ocean, continental margin, Lutzow-Holm Bay, Antarctic Peninsula, and in the volcanic regions in and around Deception Island, which helped estimate the seismic structure of Antarctica. In this chapter, a comprehensive overview of seismo-geophysical studies has been made to understand seismo-geodynamical implications for the Antarctic region in light of the Plate Reconstruction and seismo-geophysical structures of Antarctica. |
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133 |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
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ISBN |
978-3-030-87078-2 |
Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
8432 |
| Permanent link to this record |
