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1
Leary, David. "Blue Ice, Meteorites, Fossil Penguins and Rare Minerals: The Case for Enhanced Protection of Antarctica’s Unique Geoheritage – An International Legal Analysis". Yearbook of Polar Law Online 12, n. 1 (13 dicembre 2021): 17–40. http://dx.doi.org/10.1163/22116427_012010004.
Testo completoAbstract (sommario):
Its isolation and extreme climate means Antarctica is one of the world’s richest regions for untouched geoheritage. The potential of mining in Antarctica is often talked of in public discourse as a future threat to Antarctica even though the prohibition on mining is absolute and is likely to stay so indefinitely. As such mining does not pose a realistic threat to Antarctica’s geoheritage. The impacts of scientific research and tourism pose more pressing challenges to Antarctica’s geoheritage. This paper considers emerging debates in the Antarctic Treaty System on the need for further protection of Antarctica’s geoheritage. After considering the concept of geoheritage the paper considers key threats to Antarctic geoheritage. The role of Antarctic Specially Protected Area system in the protection of Antarctica’s geoheritage is then considered as is the draft code of conduct on geosciences field research currently being developed within the Antarctic Treaty System. The final part of the paper then goes on to examine how the Antarctic Treaty system could in part draw on the experience of other international initiatives, including the frameworks associated with the UNESCO Global Geoparks movement in developing an Antarctic System for protection of geoheritage.
2
BAYLY, I. A. E., J. A. E. GIBSON, B. WAGNER e K. M. SWADLING. "Taxonomy, ecology and zoogeography of two East Antarctic freshwater calanoid copepod species: Boeckella poppei and Gladioferens antarcticus". Antarctic Science 15, n. 4 (dicembre 2003): 439–48. http://dx.doi.org/10.1017/s0954102003001548.
Testo completoAbstract (sommario):
New populations of the two species of calanoid copepods known to inhabit freshwater lakes in East Antarctica, Boeckella poppei (Mrázek, 1901) and Gladioferens antarcticus Bayly, 1994, have recently been discovered. The morphology of the populations of B. poppei showed significant differences, notably a reduction in the armature of the male fifth leg, when compared with typical specimens from the Antarctic Peninsula and South America. Gladioferens antarcticus had previously been recorded from a single lake in the Bunger Hills, but has now been recorded from three further lakes in this region. A recent review of Antarctic terrestrial and limnetic zooplankton suggested that neither of these species can be considered an East Antarctic endemic, with B. poppei being listed as a recent anthropogenic introduction and G. antarcticus a ‘marine interloper’. We conclude differently: B. poppei has been present in isolated populations in East Antarctica for significant lengths of time, possibly predating the current interglacial, while G. antarcticus is a true Antarctic endemic species whose ancestors have been present in the region since before Australia separated from Antarctica.
3
Smith, R. I. Lewis, e Sally Poncet. "New southernmost record for Antarctic flowering plants". Polar Record 22, n. 139 (gennaio 1985): 425–27. http://dx.doi.org/10.1017/s0032247400005672.
Testo completoAbstract (sommario):
Smith (1982) reported the discovery in 1981 of Antarctic hair grass Deschampsia antarctica Desv. on the largest of the Refuge Islands (68° 21' S) in Marguerite Bay, off the south-west coast of Antarctic Peninsula (Figure 1). This, was at the time the southernmost record of one of Antarctica's two native flowering plants. The only ecologically suitable area for vascular plants south of these islands appeared to be the Terra Firma Islands, 40 km along the coast, which Smith had been unable to reach due to dense pack ice. Earlier reports of grass and grass-like plants on the Terra Firma Islands could not be accepted as reliable in the absence of accurate descriptions, specimens or photographs, for elsewhere the bushy grey-green or yellow lichens Usnea antarctica and U. fasciata have been mistaken for grass when viewed from a distance. However, both Deschampsia antarctica and also Antarctic pearlwort Colobanthus quitensis (Kunth) Bartl., Antarctica's other flowering plant, have now been positively identified at a site on Barn Rock (68° 42' S, 67° 32' W) in the Terra Firma group.
4
Sollman, Philip. "The genus Bryoerythrophyllum (Musci, Pottiaceae) in Antarctica". Polish Botanical Journal 60, n. 1 (1 luglio 2015): 19–25. http://dx.doi.org/10.1515/pbj-2015-0004.
Testo completoAbstract (sommario):
Abstract Antarctic material of the genus Bryoerythrophyllum P. C. Chen was studied from all specimens present in KRAM. Bryoerythrophyllum recurvirostrum (Hedw.) P. C. Chen var. antarcticum L. I. Savicz & Smirnova is treated as a distinct species: B. antarcticum (L. I. Savicz & Smirnova) P. Sollman, stat. nov. Three species are now known in the Antarctic region: B. antarcticum, B. recurvirostrum and B. rubrum (Jur. ex Geh.) P. C. Chen. Bryoerythrophyllum rubrum is reported for the first time from the Antarctic. It is a bipolar species. A key to the taxa is given. These species are described and briefly discussed, with notes on illustrations, reproduction, habitat, world range, distribution and elevation in Antarctica.
5
Beck, Peter J. "The 1991 UN session: the environmental protocol fails to satisfy the Antarctic Treaty System's critics". Polar Record 28, n. 167 (ottobre 1992): 307–14. http://dx.doi.org/10.1017/s0032247400028047.
Testo completoAbstract (sommario):
ABSTRACT1991 saw the ninth successive United Nations (UN) discussion on the ‘Question of Antarctica.’ The adoption of two more resolutions critical of the Antarctic Treaty System (ATS), including South African participation therein, reaffirmed the unchanging nature of the UN episode and the lack of consensus on the management of Antarctica. Key developments affecting Antarctica continue to occur away from New York: during 1990—91 the negotiations conducted at Vifia del Mar and Madrid for the Protocol on Environmental Protection to the Antarctic Treaty (PREP) and the measures agreed at the Bonn Antarctic Treaty Consultative Meeting proved the point. The critics of the ATS were appeased by neither PREP and its mining prohibition nor the recent dismantling of the apartheid regime in South Africa.Two UN reports were published on the state of the Antarctic environment as well as the proposed establishment of a UNsponsored research station in Antarctica. One resolution adopted in December 1991 called for annual UN reports on the Antarctic environment, although fiscal and other considerations meant that the research station proposal was effectively shelved. Another resolution urged South African exclusion from ATS meetings. The tenth annual UN discussion on Antarctica is scheduled for the close of 1992. There exists growing evidence that the critical campaign is losing momentum, although it seems premature to anticipate Antarctica's imminent demise as an UN agenda topic.
6
Cesari, Michele, Sandra J. McInnes, Roberto Bertolani, Lorena Rebecchi e Roberto Guidetti. "Genetic diversity and biogeography of the south polar water bear Acutuncus antarcticus (Eutardigrada : Hypsibiidae) – evidence that it is a truly pan-Antarctic species". Invertebrate Systematics 30, n. 6 (2016): 635. http://dx.doi.org/10.1071/is15045.
Testo completoAbstract (sommario):
Antarctica is an ice-dominated continent and all its terrestrial and freshwater habitats are fragmented, which leads to genetic divergence and, eventually, speciation. Acutuncus antarcticus is the most common Antarctic tardigrade and its cryptobiotic capabilities, small size and parthenogenetic reproduction present a high potential for dispersal and colonisation. Morphological (light and electron microscopy, karyology) and molecular (18S rRNA and cytochrome c oxidase subunit I (COI) genes) analyses on seven populations of A. antarcticus elucidated the genetic diversity and distribution of this species. All analysed populations were morphologically indistinguishable and made up of diploid females. All specimens presented the same 18S rRNA sequence. In contrast, COI analysis showed higher variability, with most Victoria Land populations presenting up to five different haplotypes. Genetic distances between Victoria Land specimens and those found elsewhere in Antarctica were low, while distances between Dronning Maud Land and specimens from elsewhere were high. Our analyses show that A. antarcticus can still be considered a pan-Antarctic species, although the moderately high genetic diversity within Victoria Land indicates the potential for speciation events. Regions of Victoria Land are considered to have been possible refugia during the last glacial maximum and a current biodiversity hotspot, which the populations of A. antarcticus mirror with a higher diversity than in other regions of Antarctica.
7
Velasco-Castrillón, Alejandro, Sandra J. McInnes, Mark B. Schultz, María Arróniz-Crespo, Cyrille A. D'Haese, John A. E. Gibson, Byron J. Adams et al. "Mitochondrial DNA analyses reveal widespread tardigrade diversity in Antarctica". Invertebrate Systematics 29, n. 6 (2015): 578. http://dx.doi.org/10.1071/is14019.
Testo completoAbstract (sommario):
Antarctica contains some of the most challenging environmental conditions on the planet due to freezing temperatures, prolonged winters and lack of liquid water. Whereas 99.7% of Antarctica is permanently covered by ice and snow, some coastal areas and mountain ridges have remained ice-free and are able to sustain populations of microinvertebrates. Tardigrades are one of the more dominant groups of microfauna in soil and limno-terrestrial habitats, but little is known of their diversity and distribution across Antarctica. Here, we examine tardigrades sampled from across an extensive region of continental Antarctica, and analyse and compare their partial mitochondrial cytochrome c oxidase subunit 1 (COI) gene sequences with those from the Antarctic Peninsula, maritime and sub-Antarctica, Tierra del Fuego and other worldwide locations in order to recognise operational taxonomic units (OTUs). From 439 new tardigrade COI sequences, we identified 98 unique haplotypes (85 from Antarctica) belonging to Acutuncus, Diphascon, Echiniscus, Macrobiotus, Milnesium and unidentified Parachela. Operational taxonomic units were delimited by Poisson tree processes and general mixed Yule coalescent methods, resulting in 58 and 55 putative species, respectively. Most tardigrades appear to be locally endemic (i.e. restricted to a single geographic region), but some (e.g. Acutuncus antarcticus (Richters, 1904)) are widespread across continental Antarctica. Our molecular results reveal: (i) greater diversity than has previously been appreciated with distinct OTUs that potentially represent undescribed species, and (ii) a lack of connectivity between most OTUs from continental Antarctica and those from other Antarctic geographical zones.
8
Thomson, M. R. A., e Alan P. M. Vaughan. "The role of Antarctica in the development of plate tectonic theories: from Scott to the present". Archives of Natural History 32, n. 2 (ottobre 2005): 362–93. http://dx.doi.org/10.3366/anh.2005.32.2.362.
Testo completoAbstract (sommario):
One hundred years of geological research in and around Antarctica since Scott's Discovery expedition of 1901–1904 have seen the continent move from a great unknown at the margins of human knowledge to centre stage in the development of plate tectonics, continental break-up and global climate evolution. Research in Antarctica has helped make the Gondwana supercontinent a scientific fact. Discoveries offshore have provided some of the key evidence for plate tectonics and extended the evidence of global glaciation back over 30 million years. Studies of Antarctica's tectonic evolution have helped elucidate the details of continental break-up, and the continent continues to provide the best testing ground for competing scientific models. Antarctica's deep past has provided support for the “Snowball Earth” hypothesis, and for the pre-Gondwana, Rodinia supercontinent. Current research is focusing on Antarctica's subglacial lakes and basins, the possible causes of Antarctic glaciation, the evolution of its surrounding oceanic and mantle gateways, and its sub-ice geological composition and structure. None of this would have been possible without maps, and these have provided the foundation stone for Antarctic research. New mapping and scientific techniques, and new research platforms hold great promise for further major contributions from Antarctica to Earth system science in the twenty-first century.
9
Chaturvedi, Sanjay. "India and the Antarctic Treaty System: Realities and Prospects". India Quarterly: A Journal of International Affairs 42, n. 4 (ottobre 1986): 351–80. http://dx.doi.org/10.1177/097492848604200401.
Testo completoAbstract (sommario):
India feels proud of its scientific as well as diplomatic achievements in regard to the Antarctica — the most forbidding terrain on ourterra firma, a significant ‘natural laboratory’ as well as an object of innovative political experiment in international control and cooperation. With as many as five successful expeditions to this multi-faceted and multi-dimensional continent, a permanently manned scientific stationDakshin Gangotri and a coveted and enviable “consultative status” in the Antarctic Treaty System, India's presence on Antarctica is well established. The Indian entry into the elitist Antarctica Treaty System (hereafter cited as ATS) and its innermost circle has added a new dimension to the geopolitics of Antarctica. It has also highlighted and reiterated, in a significant way, India's resolve to have a meaningful and effective say in the management of Antarctica and its so far untapped resources. Demonstrating its scientific maturity and political farsightedness, India has started investing in Antarctica with an eye to future returns. However, the entire issue of India-Antarctica interaction is not as it is often projected and portrayed by the press and elsewhere. Antarctica no doubt has just dawned in the realm of Indian consciousness and not many in the country possess much politico-geographic awareness about this frozen bottom of the earth where a subtle interaction between geography and politics has lately assumed significant dimensions and far reaching implications. And what we fail to grasp is the complexity of the geopolitical realities of the Antarctica and the political implications of India's presence as a consultative member within the ATS. We tend to isolate Indian interests and objectives from the general backdrop of the Antarctica political scenario and try to study them in isolation. The present essay is born out of the necessity to critically examine the Indian goals in Antarctica, irrespective of whether they are scientific, economic or political in the light of the following assumptions. Firstly, India joined the Antarctic Treaty System at a ‘critical’ juncture and at a particular ‘point’ of the evolution of the Antarctic political field and hence cannot remain insensitive to or unaffected by its problems and complexities. Secondly, while examining the Indian interests and objectives in the Antarctic we should focus our attention on the ‘role’ that India decides to play on the ‘geopolitical chessboard’ within the ATS and moreover as a consultative member with rights and duties. And finally, the annual despatch of the scientific expeditions to Antarctica and the acquisition of the “consultative status” in the ATS should not be viewed as ends in themselves but to the contrary, as indispensable means to realise some crucial objectives or goals in the Antarctica. What lies before India in regard to the Antarctica issue is a difficult and changing path and a foreign policy dilemma. It is in the light of these assumptions and against the backdrop of the Antarctica's geopolitical scenario, that the present essay purports to examine Indian interests, objectives and moves in regard to the Antarctica and the Antarctic Treaty System.
10
Strange, Carolyn. "Griffith Taylor's Antarctica: science, sentiment, and politics". Polar Record 46, n. 1 (2 settembre 2009): 65–74. http://dx.doi.org/10.1017/s0032247409008420.
Testo completoAbstract (sommario):
ABSTRACTGriffith Taylor (1880–1963) was a scientific member of the Terra Nova expedition. Although he published initially on his geomorphological, glaciological and meteorological research, conducted between 1910 and 1912, he was also a teacher, lecturer, publicist and later political commentator on Antarctica. Initially a loyal ‘Britisher’ he developed an internationalist perspective on Antarctica without compromising his self-promotional ambitions. Through his professional career in Australia, the US and Canada over the early to mid twentieth century Antarctica's shifting scientific, cultural and political history can be mapped. Just as self-interest permeated the Antarctic Treaty of 1959, so Taylor's ambitions persisted as he fashioned himself into a scientific prophet for peace. Taylor's Antarctica, an amalgam of sentiment and science, rivalry and cooperation, imperialism and internationalism, popular culture and global politics, was the twentieth century's Antarctica.
11
Smykla, Jerzy, Nataliia Iakovenko, Miloslav Devetter e Łukasz Kaczmarek. "Diversity and distribution of tardigrades in soils of Edmonson Point (Northern Victoria Land, continental Antarctica)". Czech Polar Reports 2, n. 2 (1 giugno 2012): 61–70. http://dx.doi.org/10.5817/cpr2012-2-6.
Testo completoAbstract (sommario):
This work contributes to the knowledge on distribution, diversity and ecology of the Antarctic soil biota. Different soil habitats from several ice-free coastal sites were sampled along the Victoria Land across 7° of latitude from 71° to 78°S during five austral summer seasons between 2003/04 and 2011/12. In this paper we report preliminary data on soil tardigrades (water bears) from Edmondson Point, Northern Victoria Land. Tardigrades were found to be present in 23 of the 41 examined soil samples (56%). Their presence was associated exclusively with soil samples collected from bryophytes communities and under cyanobacterial mats, whereas they were completely absent in fellfield and ornithogenic soils. Tardigrades were least numerous among all soil micrometazoans, their abundance in the positive samples was very variable and ranged from 3 to 1824 individuals per 100 g of soil DW. High water content seemed to be the major factor determining occurrence of tardigrades in the soils investigated. On the other hand low water content and toxic compounds from penguin guano seemed to act as a strong constraint on their existence in the Antarctic soils. Taxonomic evaluation of the extracted tardigrades revealed presence of only two species belonging to class Eutardigrada: Acutuncus antarcticus (Richters, 1904) and Milnesium antarcticum Tumanov, 2006. While A. antarcticus has already been reported previously as the most widespread and abundant tardigrade across the Victoria Land, the information on M. antarcticum is novel, both for Victoria Land and the continental Antarctica.
12
Stenni, Barbara, Mark A. J. Curran, Nerilie J. Abram, Anais Orsi, Sentia Goursaud, Valerie Masson-Delmotte, Raphael Neukom et al. "Antarctic climate variability on regional and continental scales over the last 2000 years". Climate of the Past 13, n. 11 (17 novembre 2017): 1609–34. http://dx.doi.org/10.5194/cp-13-1609-2017.
Testo completoAbstract (sommario):
Abstract. Climate trends in the Antarctic region remain poorly characterized, owing to the brevity and scarcity of direct climate observations and the large magnitude of interannual to decadal-scale climate variability. Here, within the framework of the PAGES Antarctica2k working group, we build an enlarged database of ice core water stable isotope records from Antarctica, consisting of 112 records. We produce both unweighted and weighted isotopic (δ18O) composites and temperature reconstructions since 0 CE, binned at 5- and 10-year resolution, for seven climatically distinct regions covering the Antarctic continent. Following earlier work of the Antarctica2k working group, we also produce composites and reconstructions for the broader regions of East Antarctica, West Antarctica and the whole continent. We use three methods for our temperature reconstructions: (i) a temperature scaling based on the δ18O–temperature relationship output from an ECHAM5-wiso model simulation nudged to ERA-Interim atmospheric reanalyses from 1979 to 2013, and adjusted for the West Antarctic Ice Sheet region to borehole temperature data, (ii) a temperature scaling of the isotopic normalized anomalies to the variance of the regional reanalysis temperature and (iii) a composite-plus-scaling approach used in a previous continent-scale reconstruction of Antarctic temperature since 1 CE but applied to the new Antarctic ice core database. Our new reconstructions confirm a significant cooling trend from 0 to 1900 CE across all Antarctic regions where records extend back into the 1st millennium, with the exception of the Wilkes Land coast and Weddell Sea coast regions. Within this long-term cooling trend from 0 to 1900 CE, we find that the warmest period occurs between 300 and 1000 CE, and the coldest interval occurs from 1200 to 1900 CE. Since 1900 CE, significant warming trends are identified for the West Antarctic Ice Sheet, the Dronning Maud Land coast and the Antarctic Peninsula regions, and these trends are robust across the distribution of records that contribute to the unweighted isotopic composites and also significant in the weighted temperature reconstructions. Only for the Antarctic Peninsula is this most recent century-scale trend unusual in the context of natural variability over the last 2000 years. However, projected warming of the Antarctic continent during the 21st century may soon see significant and unusual warming develop across other parts of the Antarctic continent. The extended Antarctica2k ice core isotope database developed by this working group opens up many avenues for developing a deeper understanding of the response of Antarctic climate to natural and anthropogenic climate forcings. The first long-term quantification of regional climate in Antarctica presented herein is a basis for data–model comparison and assessments of past, present and future driving factors of Antarctic climate.
13
Levy, Hila, Steven R. Fiddaman, Anni Djurhuus, Caitlin E. Black, Simona Kraberger, Adrian L. Smith, Tom Hart e Arvind Varsani. "Identification of Circovirus Genome in a Chinstrap Penguin (Pygoscelis antarcticus) and Adélie Penguin (Pygoscelis adeliae) on the Antarctic Peninsula". Viruses 12, n. 8 (6 agosto 2020): 858. http://dx.doi.org/10.3390/v12080858.
Testo completoAbstract (sommario):
Circoviruses infect a variety of animal species and have small (~1.8–2.2 kb) circular single-stranded DNA genomes. Recently a penguin circovirus (PenCV) was identified associated with an Adélie Penguin (Pygoscelis adeliae) with feather disorder and in the cloacal swabs of three asymptomatic Adélie Penguins at Cape Crozier, Antarctica. A total of 75 cloacal swab samples obtained from adults and chicks of three species of penguin (genus: Pygoscelis) from seven Antarctic breeding colonies (South Shetland Islands and Western Antarctic Peninsula) in the 2015−2016 breeding season were screened for PenCV. We identified new variants of PenCV in one Adélie Penguin and one Chinstrap Penguin (Pygoscelis antarcticus) from Port Charcot, Booth Island, Western Antarctic Peninsula, a site home to all three species of Pygoscelid penguins. These two PenCV genomes (length of 1986 nucleotides) share > 99% genome-wide nucleotide identity with each other and share ~87% genome-wide nucleotide identity with the PenCV sequences described from Adélie Penguins at Cape Crozier ~4400 km away in East Antarctica. We did not find any evidence of recombination among PenCV sequences. This is the first report of PenCV in Chinstrap Penguins and the first detection outside of Ross Island, East Antarctica. Given the limited knowledge on Antarctic animal viral diversity, future samples from Antarctic wildlife should be screened for these and other viruses to determine the prevalence and potential impact of viral infections.
14
Richter, Martha, e M. R. A. Thomson. "First Aspidorhynchidae (Pisces: Teleostei) from Antarctica". Antarctic Science 1, n. 1 (marzo 1989): 57–64. http://dx.doi.org/10.1017/s0954102089000106.
Testo completoAbstract (sommario):
A new fossil teleost, belonging to the family Aspidorhynchidae Nicholson & Lydekker, Aspidorhynchus antarcticus sp. nov., was obtained from a block of reworked Upper Jurassic tuffaceous mudstone in the lower (Albian) part of the mid-Cretaceous Whisky Bay Formation of James Ross Island, Antarctic Peninsula. Additional material, assignable to Aspidorhynchus sp., was collected from in situ Upper Jurassic marine rocks (Nordenskjöld Formation) at Longing Gap, northern Antarctic Peninsula. Not only is this the first reported occurrence of the family from Antarctica, it is also the first unequivocal record of Aspidorhynchus outside Europe; prior to this discovery, the genus had only been reported with certainty in marine deposits from the Middle Jurassic to Lower Cretaceous of England, France and Germany. This is the earliest neopterygian fish so far recovered from marine rocks in the Antarctic.
15
Hirose, Yuu, Takuhei Shiozaki, Masahiro Otani, Sakae Kudoh, Satoshi Imura, Toshihiko Eki e Naomi Harada. "Investigating Algal Communities in Lacustrine and Hydro-Terrestrial Environments of East Antarctica Using Deep Amplicon Sequencing". Microorganisms 8, n. 4 (31 marzo 2020): 497. http://dx.doi.org/10.3390/microorganisms8040497.
Testo completoAbstract (sommario):
Antarctica has one of the most extreme environments on Earth, with low temperatures and low nutrient levels. Antarctica’s organisms live primarily in the coastal, ice-free areas which cover approximately 0.18% of the continent’s surface. Members of Cyanobacteria and eukaryotic algae are important primary producers in Antarctica since they can synthesize organic compounds from carbon dioxide and water using solar energy. However, community structures of photosynthetic algae in Antarctica have not yet been fully explored at molecular level. In this study, we collected diverse algal samples in lacustrine and hydro-terrestrial environments of Langhovde and Skarvsnes, which are two ice-free regions in East Antarctica. We performed deep amplicon sequencing of both 16S ribosomal ribonucleic acid (rRNA) and 18S rRNA genes, and we explored the distribution of sequence variants (SVs) of these genes at single nucleotide difference resolution. SVs of filamentous Cyanobacteria genera, including Leptolyngbya, Pseudanabaena, Phormidium, Nodosilinea, Geitlerinama, and Tychonema, were identified in most of the samples, whereas Phormidesmis SVs were distributed in fewer samples. We also detected unicellular, multicellular or heterocyst forming Cyanobacteria strains, but in relatively small abundance. For SVs of eukaryotic algae, Chlorophyta, Cryptophyta, and Ochrophyta were widely distributed among the collected samples. In addition, there was a red colored bloom of eukaryotic alga, Geminigera cryophile (Cryptophyta), in the Langhovde coastal area. Eukaryotic SVs of Acutuncus antarcticus and/or Diphascon pingue of Tardigrada were dominant among most of the samples. Our data revealed the detailed structures of the algal communities in Langhovde and Skarvsnes. This will contribute to our understanding of Antarctic ecosystems and support further research into this subject.
16
Wendt, Anke S., Alan P. M. Vaughan e Adrian J. Boyce. "Precipitation trapped in datable rock-forming minerals: estimating Antarctic palaeoelevations - a discussion". Antarctic Science 18, n. 1 (marzo 2006): 123–39. http://dx.doi.org/10.1017/s0954102006000125.
Testo completoAbstract (sommario):
Meteoric water that interacted with minerals during retrogressive metamorphism and hydrothermalism in the late-stage of mountain building processes contains hydrogen and oxygen isotopes that are potential proxies for palaeoelevation reconstruction in Antarctica. The effects of temperature on meteoric isotopic signatures, meteoric crustal infiltration processes, and the mechanisms of capture and preservation of meteoric δD and δ18O values in rock-forming minerals are discussed. Special emphasis is given to Antarctica’s geographical high-latitude position and climatic fluctuations over time and to the highmountain ranges of continental Antarctica, which were tectonically active regions in the past. In this context, a new compilation of recent Antarctic snow and ice δD and δ18O data is presented, by which we demonstrate that net elevations versus isotopic depletions are positively correlated for continental Antarctica - a prime requisite when estimating palaeoelevations.
17
Sirenko, B. I. "First finding of a widely distributed Antarctic chiton species (Mollusca: Polyplacophora) in the North Pacific". Ruthenica, Russian Malacological Journal 29, n. 1 (14 gennaio 2019): 71–74. http://dx.doi.org/10.35885/ruthenica.2019.29(1).3.
Testo completoAbstract (sommario):
For the first time, the widely spread Antarctic species Leptochiton antarcticus was found at the Emperor Seamounts in the North Pacific Ocean. In spite of a large distance between the Emperor Seamounts and Antarctica, the found specimen have very similar shell, girdle, radula and gill features to the type material. I propose that L. antarcticus spread to the North Pacific from the Antarctic via a deep-water current near the ocean floor, and perhaps it inhabits the slopes of islands and continents from the South Ocean to the Emperor Seamounts.
18
Soares, Fernanda Codevilla, e Andrés Zarankin. "Sensing Antarctica". Revista Arqueologia Pública 14, n. 1 (22 giugno 2020): 182–98. http://dx.doi.org/10.20396/rap.v14i1.8660182.
Testo completoAbstract (sommario):
Full of superlatives, the Antarctic continent has been represented as the most desert, coldest and wildest location of all places on earth; an apt location for archeology, a discipline often associated with adventure. To reflect on these considerations and critique the traditional ways of presenting Archaeology and Antarctica in science, LEACH-UFMG has proposed an alternative mediation that encourages communication with both. Using exhibits, plays, comic books, sticker albums, among others, the idea is to use the elements that normally make Antarctica and Archaeology interesting for people without, however, oversimplifying. Specifically in this paper we will report an experience that we had at Espaço do Conhecimento UFMG which was a sensorial exhibit, resulting from the collaborative work of Mediantar (Antarctica Medicine), Mycoantar (Antarctica Microbiology) and “White Landscape” (Antarctic Archaeology and Anthropology) projects, all carried out by UFMG. This exhibit called “Antarctic expedition” was on display from December 7th 2017 to May 20th 2018 and was visited by 30573 people.
19
Pfeifer, Christian, Marie-Charlott Rümmler e Osama Mustafa. "Assessing colonies of Antarctic shags by unmanned aerial vehicle (UAV) at South Shetland Islands, Antarctica". Antarctic Science 33, n. 2 (14 gennaio 2021): 133–49. http://dx.doi.org/10.1017/s0954102020000644.
Testo completoAbstract (sommario):
AbstractDue to the remote location of colonies of Antarctic shags (Phalacrocorax (atriceps) bransfieldensis) in Antarctica, there is only sparse data on the abundance of this species. An unmanned aerial vehicle (UAV) survey for known and unknown Antarctic shag colonies along the coasts of Nelson Island and western King George Island, Antarctica, was conducted in December 2016. Four colonies, one of them previously unknown, were detected. For the first time since the 1980s, the total population size of the colonies in that area was determined. A comparison with previous estimates revealed evidence of a population increase by a factor of 2.86. To support future survey campaigns, several characteristic features of Antarctic shag colonies, nests and individuals in aerial imagery were identified. This makes possible more reliable detection and determination of population size in Antarctic shag colonies. These characteristic features were compared with those of chinstrap penguin colonies (Pygoscelis antarcticus) because these species often overlap spatially and are difficult to distinguish. In addition, the optimal weather conditions and flight parameters for an aerial survey were specified.
20
Dethloff, Klaus, Ksenia Glushak, Annette Rinke e Dörthe Handorf. "Antarctic 20th Century Accumulation Changes Based on Regional Climate Model Simulations". Advances in Meteorology 2010 (2010): 1–14. http://dx.doi.org/10.1155/2010/327172.
Testo completoAbstract (sommario):
The regional climate model HIRHAM has been applied to Antarctica driven at the lateral and lower boundaries by European Reanalysis data ERA-40 for the period 1958–1998. Simulations over 4 decades, carried out with a horizontal resolution of 50 km, deliver a realistic simulation of the Antarctic atmospheric circulation, synoptic-scale pressure systems, and the spatial distribution of precipitation minus sublimation (P-E) structures. The simulated P-E pattern is in qualitative agreement with glaciological estimates. The estimated (P-E) trends demonstrate surfacemass accumulation increase at the West Antarctic coasts and reductions in parts of East Antarctica. The influence of the Antarctic Oscillation (AAO) on the near-surface climate and the surface mass accumulation over Antarctica have been investigated on the basis of ERA-40 data and HIRHAM simulations. It is shown that the regional accumulation changes are largely driven by changes in the transient activity around the Antarctic coasts due to the varying AAO phases. During positive AAO, more transient pressure systems travelling towards the continent, and Western Antarctica and parts of South-Eastern Antarctica gain more precipitation and mass. Over central Antarctica the prevailing anticyclone causes a strengthening of polar desertification connected with a reduced surface mass balance in the northern part of East Antarctica.
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KITAURA, Marcos J., Mayara C. SCUR, Adriano A. SPIELMANN e Aline P. LORENZ-LEMKE. "A revision ofLeptogium(Collemataceae, lichenized Ascomycota) from Antarctica with a key to species". Lichenologist 50, n. 4 (luglio 2018): 467–85. http://dx.doi.org/10.1017/s0024282918000269.
Testo completoAbstract (sommario):
AbstractWith more than 180 known species,Leptogiumhas its greatest richness in tropical regions. Only three species have so far been reported from Antarctica but extensive surveys in the Antarctic Maritime Islands have shown that this is an underestimate.Leptogium antarcticum(non-isidiate, with medulla composed of columnar hyphae),L. marcellii(non-isidiate, with medulla composed of a sponge-like arrangement of hyphae) andL. tectum(isidiate, with medulla composed of columnar hyphae) are described here as new to science. The new species are compared with those already reported for the genus in Antarctica, namelyL. crispatellum,L. menziesiiandL. puberulum, and an identification key is provided. Sequences of ITS and mrSSU regions were obtained from recently collectedL. antarcticum,L. marcellii,L. puberulumandL. tectumspecimens. Morphological and anatomical data were compared along with available genetic data in order to delimit these species more accurately, using an integrative approach.
22
Xie, Aihong, Jiangping Zhu, Xiang Qin e Shimeng Wang. "The Antarctic Amplification Based on MODIS Land Surface Temperature and ERA5". Remote Sensing 15, n. 14 (14 luglio 2023): 3540. http://dx.doi.org/10.3390/rs15143540.
Testo completoAbstract (sommario):
With global warming accelerating, polar amplification is one of the hot issues in climate research. However, most studies focus on Arctic amplification, and little attention has been paid to Antarctic amplification (AnA), and there is no relevant research based on MODIS (Moderate Resolution Imaging Spectroradiometer) land surface temperature observations. Compared with 128 stations’ observations, MODIS can capture the variations in temperature over Antarctica. In addition, the temperature changes in Antarctica, East Antarctica, West Antarctica and the Antarctic Peninsula during the period 2001–2018 reflected by the MODIS and ERA5 are basically consistent, and the temperature changes in Antarctica are negatively correlated with the Southern Annular Mode. AnA occurs under all annual and seasonal scales, with an AnA index greater than 1.27 (1.31) from the MODIS (ERA5), and is strongest in the austral winter and weakest in summer. AnA displays regional differences, and the signal from the MODIS is similar to that from ERA5. The strongest amplification occurs in East Antarctica, with an AnA index greater than 1.45 (1.48) from the MODIS (ERA5), followed by West Antarctica, whereas the amplified signal is absent at the Antarctic Peninsula. In addition, seasonal differences can be observed in the sub regions of Antarctica. For West Antarctica, the greatest amplification appears in austral winter, and in austral spring for East Antarctica. The AnA signal also can be captured in daytime and nighttime observations, and the AnA in nighttime observations is stronger than that in daytime. Generally, the MODIS illustrates the appearance of AnA for the period 2001–2018, and the Antarctic climate undergoes drastic changes, and the potential impact should arouse attention.
23
Flores, Carolina. "An Ecological Reading of Sovereignty Claims in Antarctica". Yearbook of Polar Law Online 13, n. 1 (19 aprile 2022): 210–30. http://dx.doi.org/10.1163/22116427_013010011.
Testo completoAbstract (sommario):
Abstract Article IV of the Antarctic Treaty has “frozen” the controversies over sovereignty in Antarctica. However, the seven States claiming sovereignty over the continent still have an important role in the Antarctic Treaty System. One of the areas where they show leadership is in environmental protection, which is a pivotal principle of Antarctica’s regime since the adoption of the Environmental Protocol in 1991. Their active role cannot be explained under a Westphalian interpretation of sovereignty, where states have absolute power over the exploitation of their natural resources. Notwithstanding, under a human-based interpretation of sovereignty, the conduct of the Claimant States may have a clearer explanation. This article will look into the practices of the Claimant States over the Antarctic to understand if and how their sovereignty claims may be linked to environmental protection.
24
Jun, Sang-Yoon, Joo-Hong Kim, Jung Choi, Seong-Joong Kim, Baek-Min Kim e Soon-Il An. "The internal origin of the west-east asymmetry of Antarctic climate change". Science Advances 6, n. 24 (giugno 2020): eaaz1490. http://dx.doi.org/10.1126/sciadv.aaz1490.
Testo completoAbstract (sommario):
Recent Antarctic surface climate change has been characterized by greater warming trends in West Antarctica than in East Antarctica. Although this asymmetric feature is well recognized, its origin remains poorly understood. Here, by analyzing observation data and multimodel results, we show that a west-east asymmetric internal mode amplified in austral winter originates from the harmony of the atmosphere-ocean coupled feedback off West Antarctica and the Antarctic terrain. The warmer ocean temperature over the West Antarctic sector has positive feedback, with an anomalous upper-tropospheric anticyclonic circulation response centered over West Antarctica, in which the strength of the feedback is controlled by the Antarctic topographic layout and the annual cycle. The current west-east asymmetry of Antarctic surface climate change is undoubtedly of natural origin because no external factors (e.g., orbital or anthropogenic factors) contribute to the asymmetric mode.
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Ahn, In-Young, Francyne Elias-Piera, Sun-Yong Ha, Sergio Rossi e Dong-U. Kim. "Seasonal Dietary Shifts of the Gammarid Amphipod Gondogeneia antarctica in a Rapidly Warming Fjord of the West Antarctic Peninsula". Journal of Marine Science and Engineering 9, n. 12 (17 dicembre 2021): 1447. http://dx.doi.org/10.3390/jmse9121447.
Testo completoAbstract (sommario):
The amphipod Gondogeneia antarctica is among the most abundant benthic organisms, and a key food web species along the rapidly warming West Antarctic Peninsula (WAP). However, little is known about its trophic strategy for dealing with the extreme seasonality of Antarctic marine primary production. This study, using trophic markers, for the first time investigated seasonal dietary shifts of G. antarctica in a WAP fjord. We analyzed δ13C and δ15N in G. antarctica and its potential food sources. The isotopic signatures revealed a substantial contribution of red algae to the amphipod diet and also indicated a significant contribution of benthic diatoms. The isotope results were further supported by fatty acid (FA) analysis, which showed high similarities in FA composition (64% spring–summer, 58% fall–winter) between G. antarctica and the red algal species. G. antarctica δ13C showed a small shift seasonally (−18.9 to −21.4‰), suggesting that the main diets do not change much year-round. However, the relatively high δ15N values as for primary consumers indicated additional dietary sources such as animal parts. Interestingly, G. antarctica and its potential food sources were significantly enriched with δ15N during the fall–winter season, presumably through a degradation process, suggesting that G. antarctica consumes a substantial portion of its diets in the form of detritus. Overall, the results revealed that G. antarctica relies primarily on food sources derived from benthic primary producers throughout much of the year. Thus, G. antarctica is unlikely very affected by seasonal Antarctic primary production, and this strategy seems to have allowed them to adapt to shallow Antarctic nearshore waters.
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Enzenbacher, Debra J. "Tourists in Antarctica: numbers and trends". Polar Record 28, n. 164 (gennaio 1992): 17–22. http://dx.doi.org/10.1017/s0032247400020210.
Testo completoAbstract (sommario):
AbstractApproximately 39 000 tourists have visited Antarctica since 1957; numbers peryearare provided. Abrief history of sea and airborne tourism in Antarctica reveals past and current trends. The formation of the International Association of Antarctica Tour Operators and its role in the self-regulated tourism industry in Antarctica are considered, together with the implications of recently-promulgated Antarctic Treaty Recommendation XVI-13. The number of tourists visiting Antarctica is shown to exceed the combined number of scientists and support personnel from all National Antarctic Programs. It is concluded that the ATS provides a suitable framework within which to develop measures to protect Antarctica from tourist activity. However, regulations developed must be based on hard data on the size and impact of the industry to be effectively implemented.
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Hemmings, Alan D., Sanjay Chaturvedi, Elizabeth Leane, Daniela Liggett e Juan Francisco Salazar. "Nationalism in Today’s Antarctic". Yearbook of Polar Law Online 7, n. 1 (5 dicembre 2015): 531–55. http://dx.doi.org/10.1163/2211-6427_020.
Testo completoAbstract (sommario):
Whilst nationalism is a recognised force globally, its framing is predicated on experience in conventionally occupied parts of the world. The familiar image of angry young men waving Kalashnikovs means that the idea that nationalism might be at play in Antarctica has to overcome much instinctive resistance, as well as the tactical opposition of the keepers of the present Antarctic political arrangements. The limited consideration of nationalism in Antarctica has generally been confined to the past, particularly “Heroic-Era” and 1930s–1940s expeditions. This article addresses the formations of nationalism in the Antarctic present. Antarctic nationalism need not present in the same shape as nationalisms elsewhere to justify being called nationalism. Here it occurs in a virtual or mediated form, remote from the conventional metropolitan territories of the states and interests concerned. The key aspect of Antarctic nationalism is its contemporary form and intensity. We argue that given the historic difficulties of Antarctic activities, and the geopolitical constraints of the Cold War, it has only been since the end of that Cold War that a more muscular nationalism has been able to flourish in Antarctica. Our assessment is that there at least 11 bases upon which Antarctic nationalism might arise: (i) formally declared claims to territorial sovereignty in Antarctica; (ii) relative proximity of Antarctica to one’s metropolitan territory; (iii) historic and institutional associations with Antarctica; (iv) social and cultural associations; (v) regional or global hegemonic inclinations; (vi) alleged need in relation to resources; (vii) contested uses or practices in Antarctica; (viii) carry-over from intense antipathies outside Antarctica; (ix) national pride in, and mobilisation through, national Antarctic programmes; (x) infrastructure and logistics arrangements; or (xi) denial or constraint of access by one’s strategic competitors or opponents. In practice of course, these are likely to be manifested in combination. The risks inherent in Antarctic nationalism are the risks inherent in unrestrained nationalism anywhere, compounded by its already weak juridical situation. In Antarctica, the intersection of nationalism with resources poses a particular challenge to the regional order and its commitments to shareable public goods such as scientific research and environmental protection.
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Storey, Bryan C., e Roi Granot. "Chapter 1.1 Tectonic history of Antarctica over the past 200 million years". Geological Society, London, Memoirs 55, n. 1 (2021): 9–17. http://dx.doi.org/10.1144/m55-2018-38.
Testo completoAbstract (sommario):
AbstractThe tectonic evolution of Antarctica in the Mesozoic and Cenozoic eras was marked by igneous activity that formed as a result of simultaneous continental rifting and subduction processes acting during the final stages of the southward drift of Gondwana towards the South Pole. For the most part, continental rifting resulted in the progressive disintegration of the Gondwana supercontinent from Middle Jurassic times to the final isolation of Antarctica at the South Pole following the Cenozoic opening of the surrounding ocean basins, and the separation of Antarctica from South America and Australia. The initial rifting into East and West Gondwana was proceeded by emplacement of large igneous provinces preserved in present-day South America, Africa and Antarctica. Continued rifting within Antarctica did not lead to continental separation but to the development of the West Antarctic Rift System, dividing the continent into the East and West Antarctic plates, and uplift of the Transantarctic Mountains. Motion between East and West Antarctica has been accommodated by a series of discrete rifting pulses with a westward shift and concentration of the motion throughout the Cenozoic leading to crustal thinning, subsidence, elevated heat flow conditions and rift-related magmatic activity. Contemporaneous with the disintegration of Gondwana and the isolation of Antarctica, subduction processes were active along the palaeo-Pacific margin of Antarctica recorded by magmatic arcs, accretionary complexes, and forearc and back-arc basin sequences. A low in magmatic activity between 156 and 142 Ma suggests that subduction may have ceased during this time. Today, following the gradual cessation of the Antarctic rifting and surrounding subduction, the Antarctic continent is situated close to the centre of a large Antarctic Plate which, with the exception of an active margin on the northern tip of the Antarctic Peninsula, is surrounded by active spreading ridges.
29
Thompson, Keith. "Antarctic Ecology and Antarctica". Journal of the Royal Society of New Zealand 16, n. 1 (marzo 1986): 111–17. http://dx.doi.org/10.1080/03036758.1986.10426960.
Testo completo
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Chaturvedi, Sanjay. "Antarctica and the United Nations". India Quarterly: A Journal of International Affairs 42, n. 1 (gennaio 1986): 1–26. http://dx.doi.org/10.1177/097492848604200101.
Testo completoAbstract (sommario):
During the 200-odd years, since the circumnavigation of the Antarctica by-Captain James Cook (1772–1775), international interest in the continent has grown to such an extent that the frozen Antarctica is now at the centre of a heated political debate. The prophecy of Captain Cook that the world would derive no profit out of it, seems to be proving wrong. Antarctica has now ceased to be merely the most significant ‘natural laboratory’ and the site of important scientific experiments, it has become, under the Antarctic Treaty of 1959, a subject of ‘innovative political experiment’ in multilateral administration.1 The surrounding oceans, where seals and whales were once-recklessly exploited, today harbour a new and fast growing fishery of immense potential,2 while the prospect of offshore oil and gas exploitation lies on the horizon. With the tantalising speculations regarding the existence of more than hundred onland minerals in Antarctica (including gold, copper, lithium and uranium), it is only natural that an increasing number of states should' take interest in this so far unnoticed mine.3 Divergence of national interests, perceptions and positions within the-Antarctica Treaty System in regard to who owns the Antarctic audits: resources—particularly between the Antarctica claimants and the non-claimants—has always led to tensions, latent as well as manifest, within the Treaty System; recently a series of new developments like the United Nations' involvement in the Antarctic question have added to the complexity of the Antarctic political scenario. They have serious future implications for the delicate political equilibrium so far maintained on the continent under the Antarctic Treaty. The questions asked today are: Who owns the Antarctic and how significant are the benefits To be derived out of it? Who is to profit from them? and To what extent the possible uses of Antarctica are-compatible with each other? The essay purports to critically examine, in a historical perspective, the nature, scope and implications of the interaction between the United Nations and the Antarctic Treaty System. While taking note of the earlier attempts made to make possible a UN control of Antarctica, the Antarctic Treaty of 1959 and the functioning thereof during the ‘sixties’ and ‘seventies’, we shall focus our attention on the recent endeavour of some countries to involve the United Nations in the Antarctic Question. The study would include, of course, the nature and scope of the United Nations study of theQuestion of Antarctica ( November 1984) and the ensuing discussions. Thus we shall examine the perceptions of various states, and of the desirability and extent of the role UN might play in Antarctica. We shall also take a special note of India's stand in this regard.
31
Zhu, Jiangping, Aihong Xie, Xiang Qin, Bing Xu e Yicheng Wang. "Assessment of Antarctic Amplification Based on a Reconstruction of Near-Surface Air Temperature". Atmosphere 14, n. 2 (20 gennaio 2023): 218. http://dx.doi.org/10.3390/atmos14020218.
Testo completoAbstract (sommario):
Polar amplification has been a research focus in climate research in recent decades. However, little attention has been paid to Antarctic amplification (AnA). We have examined the variations in annual and seasonal temperature over the Antarctic Ice Sheet and its amplification based on reconstruction covering the period 2002–2018. The results show the occurrence of annual and seasonal AnA, with an AnA index greater than 1.39 with seasonal differences, and that AnA is strong in the austral winter and spring. Moreover, AnA displays regional differences, with the greatest amplification occurring in East Antarctica, with an AnA index greater than 1.51, followed by West Antarctica. AnA is always absent in the Antarctic Peninsula. In addition, amplification in East Antarctica is most conspicuous in spring, which corresponds to the obvious warming in this season; and the spring amplification signal is weakest for West Antarctica. When considering the influence of the ocean, the AnA becomes obvious, compared to when only the land is considered. Southern Annular Mode (SAM), surface pressure and westerlies work together to affect the temperature change over Antarctica and AnA; and SAM and surface pressure are highly correlated with the temperature change over East Antarctica. The picture reflects the accelerated changes in Antarctic temperature.
32
WALL, DIANA H. "Biodiversity and ecosystem functioning in terrestrial habitats of Antarctica". Antarctic Science 17, n. 4 (18 novembre 2005): 523–31. http://dx.doi.org/10.1017/s0954102005002944.
Testo completoAbstract (sommario):
Are we failing to acknowledge the impact of global changes (e.g. UVB, invasive species, climate, land use, atmosphere) on the terrestrial biodiversity and ecosystem processes of Antarctica? Antarctica is considered a pristine environment and has low terrestrial species diversity and trophic complexity, and yet while scientifically possible, we still do not know the number of species, where they are, or how their influence on ecosystem processes (e.g. nutrient cycling, carbon flux, decomposition, feedbacks to climate, hydrology) will be affected by multiple global changes. Increased recognition of human dependence on services provided by biodiversity and ecosystem functioning combined with documented impacts of global change already occurring on Antarctic soil ecosystems, increases the urgency to expand investigations regionally in Antarctica. We cannot measure the effects of global change or sustainably manage Antarctica's future if we underestimate the contribution of soil communities. Evidence indicates habitats of rocky moraines, soils and cyroconite holes of glaciers in the continental interior may host not only microbes, but also a complexity of algae and invertebrates. Scientists of many disciplines, together, need to assess the benefits humans derive from Antarctic terrestrial biodiversity and ecosystem processes, how these will be affected by global change, and link their findings to the rest of the world.
33
Powell, Robert B., Stephen R. Kellert e Sam H. Ham. "Antarctic tourists: ambassadors or consumers?" Polar Record 44, n. 3 (luglio 2008): 233–41. http://dx.doi.org/10.1017/s0032247408007456.
Testo completoAbstract (sommario):
ABSTRACTTwo complementary studies were conducted to investigate both the immediate and longer-term influence of Antarctic cruise tourism experiences on participants’ knowledge of Antarctica, attitudes toward management issues facing the Antarctic region, and environmental behaviours and future intentions. In addition, the study investigated tourists’ attitudes toward visitor guidelines. The results suggest that Antarctica nature-based tourism operators have the potential to provide experiences that educate the public to the importance of Antarctica.
34
Hawes, T. C., M. R. Worland, P. Convey e J. S. Bale. "Aerial dispersal of springtails on the Antarctic Peninsula: implications for local distribution and demography". Antarctic Science 19, n. 1 (28 febbraio 2007): 3–10. http://dx.doi.org/10.1017/s0954102007000028.
Testo completoAbstract (sommario):
Aerial dispersal has been frequently proposed as a potential mechanism by which polar terrestrial arthropods are transported to, and settle the ice free habitats of Antarctica, but to date there has been little substantive evidence in support of this hypothesis. Using water traps we investigated aerial deposition of arthropods on Lagoon Island, Ryder Bay, on the Antarctic Peninsula. Over a period of five weeks, trapping at three different altitudes, we captured a total of nine springtails, Cryptopygus antarcticus, all alive. This is the first study to demonstrate conclusively the survival of wind-borne native arthropods within Antarctica. By scaling the modest trapping area and success against island surface area, it is clear that hundreds, if not thousands, of springtails are regularly relocated by winds between the terrestrial habitats of Marguerite Bay. We use known desiccation rates of C. antarcticus and wind speeds to predict the likelihood of successful dispersal between the principal terrestrial habitats of the larger Marguerite Bay. Implications for local and long-range dispersal are discussed in relation to C. antarcticus and other polar arthropods.
35
Liggett, Daniela, Bob Frame, Neil Gilbert e Fraser Morgan. "Is it all going south? Four future scenarios for Antarctica". Polar Record 53, n. 5 (settembre 2017): 459–78. http://dx.doi.org/10.1017/s0032247417000390.
Testo completoAbstract (sommario):
ABSTRACTThe future is uncertain for Antarctica, with many possibilities – some more plausible, others more preferable. Indeed, the region and its governance regime may be reaching (or may have reached) a crossroads moment as a result of a series of challenges, including the changing Antarctic climate and environment, increasing human activity, shifting values among Antarctic states and a low-cost, somewhat benign governance regime (the Antarctic Treaty System). Within this context there are a number of interdependent drivers that are likely to influence Antarctica's future over, say, 25 years: global environmental and socio-economic developments; Antarctic governance; Antarctic research, including national Antarctic programme operations; and Antarctic tourism. The research presented here involved a thorough examination of Antarctic literature on current Antarctic developments and challenges, and an assessment of global trends. Scenarios were developed through a facilitated workshop process. From these, four future scenarios were developed based on interactions between these drivers. The resulting scenarios provide a dynamic, evolving possibility space to be explored as a means of understanding where Antarctic issues might evolve, depending on the growth or diminishing importance of drivers. In turn these suggest that more structured polar futures are needed based on formal quantitative and qualitative data.
36
Taboada, Sergi, Luis Francisco García-Fernández, Santiago Bueno, Jennifer Vázquez, Carmen Cuevas e Conxita Avila. "Antitumoural activity in Antarctic and sub-Antarctic benthic organisms". Antarctic Science 22, n. 5 (19 luglio 2010): 494–507. http://dx.doi.org/10.1017/s0954102010000416.
Testo completoAbstract (sommario):
AbstractA prospecting search for antitumoural activity in polar benthic invertebrates was conducted on Antarctic and sub-Antarctic benthos in three different areas: Bouvet Island (sub-Antarctic), eastern Weddell Sea (Antarctica) and the South Shetland Islands (Antarctica). A total of 770 benthic invertebrate samples (corresponding to at least 290 different species) from 12 different phyla were assayed to establish their pharmacological potential against three human tumour cell lines (colorectal adenocarcinoma, lung carcinoma and breast adenocarcinoma). Bioassays resulted in 15 different species showing anticancer activity corresponding to five different phyla: Tunicata (5), Porifera (4), Cnidaria (3), Echinodermata (2) and Annelida (1). This appears to be the largest pharmacological study ever carried out in Antarctica and it shows very promising antitumoural activities in the Antarctic and sub-Antarctic benthos.
37
Daneri, G. A., e A. R. Carlini. "Spring and summer predation on fish by the Antarctic fur seal, Arctocephalus gazella, at King George Island, South Shetland Islands". Canadian Journal of Zoology 77, n. 7 (20 ottobre 1999): 1157–60. http://dx.doi.org/10.1139/z99-064.
Testo completoAbstract (sommario):
The fish component of the diet of nonbreeding male Antarctic fur seals, Arctocephalus gazella, was analyzed from 70 scats collected at Stranger Point, King George Island, South Shetland Islands, during the austral spring (n = 36) and summer (n = 34) of 1993-1994. Fish occurred in approximately 70% of scats that contained food remains irrespective of season. In spring, the main fish prey were Electrona antarctica, Pleuragramma antarcticum, and Notolepis coatsi, which together gave two-thirds of the 110 otoliths recovered. In summer, 457 otoliths were retrieved; the most frequent and abundant species were Gymnoscopelus nicholsi, E. antarctica, and P. antarcticum, which represented over 80% of the otoliths recovered. A substantial increase in the amount of fish ingested by fur seals occurred from spring to summer concomitant with a change in the relative proportion of fish taxa. Most fish species identified are pelagic and feed on krill. During the study period, commercial fishing in the area was not based upon any of the fish species identified.
38
Beck, Peter J. "Identifying national interests in Antarctica: the case of Canada". Polar Record 32, n. 183 (ottobre 1996): 335–46. http://dx.doi.org/10.1017/s0032247400067553.
Testo completoAbstract (sommario):
ABSTRACTDuring the past decade, most publications on Antarctic politics and law have concentrated upon broader developments at the Antarctic Treaty System (ATS) level. Less attention has been devoted to the nature of national interests in Antarctica and ways of balancing different policy objectives through time. Canada, though failing to accede to the Antarctic Treaty until 1988, offers a useful case study illuminating the broad range of interests influencing the policy of individual governments toward Antarctica, and particularly the reasons why states lacking clear national interests therein participate in the ATS. For Canada, Antarctica has always been viewed principally from an Arctic perspective. The resulting low priority of Antarctica explains Canada's initial non-involvement in the ATS. However, by the late 1980s, accession to the Antarctic Treaty was deemed desirable on policy grounds, even if Canada assumed only alow key role in the ATS, at least until 1994–1995, when the appointment of an Ambassador for Circumpolar Affairs was apparently followed by a more active bi-polar strategy.
39
Yiğit, Merve Kahraman, e Mehmet Gökhan Halıcı. "A NEW LICHENIZED FUNGI RECORD FROM ANTARCTIC PENINSULA, ANTARCTICA ACCORDING TO nrITS PHYLOGENY: Buellia badia (FR.) A. MASSAL". CURRENT TRENDS IN NATURAL SCIENCES 12, n. 23 (31 luglio 2023): 321–26. http://dx.doi.org/10.47068/ctns.2023.v12i23.038.
Testo completoAbstract (sommario):
Vegetation in the Antarctic Peninsula is quite poor due to the generally harsh conditions of Antarctica. Lichenized fungi are the dominant elements of the vegetation. There are about 450 species of lichenized fungi in Antarctica. About 65% of these lichenized fungi are distributed in the Antarctic Peninsula. Buellia is one of the most common genera in the Antarctic Peninsula. The genus Buellia is characterized by black lecideine apothecia, oblong or ellipsoidal and rarely citriform-shaped brown ascospores with one or more septa and a reddish-brown and rarely hyaline hypothecium. It is classified in the Caliciaceae family. The phylogeny of the heterogeneous genus Buellia is still not fully resolved today. There are about 400 species in the genus Buellia in the world. Only 20 of these species are distributed in Antarctica. In this study, we report Buellia badia as a new lichenized fungi record from Antarctic Peninsula, Antarctica according to its nrITS phylogeny.
40
Brady, Anne-Marie. "New Zealand's strategic interests in Antarctica". Polar Record 47, n. 2 (15 giugno 2010): 126–34. http://dx.doi.org/10.1017/s0032247410000148.
Testo completoAbstract (sommario):
ABSTRACTNew Zealand has important strategic interests in Antarctica that are as much about geography and the country's geostrategic needs, as they are about history and the politics of maintaining rights gained in an earlier era. This paper outlines the reasons behind New Zealand's involvement in and commitment to Antarctica; profiles the various bodies involved in maintaining and negotiating New Zealand's Antarctic presence and voice on Antarctic affairs; and discusses New Zealand's core interests in the Antarctic continent that help to shape its Antarctic policy.
41
Allen, Claire S. "Proxy development: a new facet of morphological diversity in the marine diatom <i>Eucampia antarctica</i> (Castracane) Mangin". Journal of Micropalaeontology 33, n. 2 (1 settembre 2014): 131–42. http://dx.doi.org/10.1144/jmpaleo2013-025.
Testo completoAbstract (sommario):
Abstract. The varied aspect ratios observed in the Antarctic marine diatom Eucampia antarctica are described and quantified. Data are compiled from detailed measurements of the gross morphology of winter stage specimens found in samples of modern marine sediments. Surface sediment samples come from a range of oceanographic settings spanning almost 20° of latitude from north of the Polar Front in the SW Atlantic to close to continental Antarctica in the southern Amundsen Sea. Results are compared with previously recorded morphological data ascribed to the polar and sub-polar varieties of E. antarctica (E. antarctica var recta and E. antarctica var antarctica) and reveal that the aspect ratio of both varieties responds independently of symmetry and colony structure. The discussion considers the likely basis of the observed aspect ratio distribution and whether the morphological diversity offers any potential for use as proxy evidence in Antarctic palaeoceanographic reconstructions. Although it requires further study, valve symmetry offers promising potential as a quantitative proxy for austral summer sea surface temperatures.
42
Storey, J. W. V. "Astronomy and Astrophysics from Antarctica: a new SCAR Scientific Research Program". Proceedings of the International Astronomical Union 5, H15 (novembre 2009): 616–17. http://dx.doi.org/10.1017/s1743921310010768.
Testo completoAbstract (sommario):
AbstractIn July 2008 the IAU became a union member of the ICSU body SCAR—the Scientific Committee on Antarctic Research. At the same time, SCAR initiated a Planning Group to establish a Scientific Research Program in Astronomy and Astrophysics from Antarctica. Broadly stated, the objectives of Astronomy and Astrophysics from Antarctica are to coordinate astronomical activities in Antarctica in a way that ensures the best possible outcomes from international investment in Antarctic astronomy, and maximizes the opportunities for productive interaction with other disciplines.
43
Long, Douglas J. "Quaternary colonization or Paleogene persistence?: historical biogeography of skates (Chondrichthyes: Rajidae) in the Antarctic ichthyofauna". Paleobiology 20, n. 2 (1994): 215–28. http://dx.doi.org/10.1017/s0094837300012690.
Testo completoAbstract (sommario):
Seven endemic species of skates (Chondrichthyes: Rajidae) represent the only family of elasmobranchs currently known to live in Antarctic continental waters. Many previous authors believed skates colonized Antarctic waters from Patagonia during interglacial periods in the Quaternary. However, recent fossil material collected from the middle Eocene La Meseta Formation of Seymour Island, Antarctic Peninsula, indicates that they may have persisted in Antarctic waters since the Paleogene. Additionally, oceanographic barriers present in the Neogene and Quaternary would have prevented dispersal from southern continents to Antarctica. A revised dispersal scenario, based on skate fossils, biology, paleogeography, and present centers of skate diversity, suggests that skates evolved in the western Tethys and North Boreal seas of western Europe in the Late Cretaceous and early Paleogene and emigrated into Antarctica during the early to middle Eocene via a dispersal corridor along the continental margins of the western Atlantic Ocean. Skates probably populated the Pacific Basin by passing from this dispersal corridor through the Arctic Ocean. Vicariant events, such as opening of the Drake Passage, the development of the Circum-Antarctic Current, and formation of deep and wide basins around Antarctica in the late Paleogene, created barriers that isolated some species of skates in Antarctica and prevented movement of other species of skates into Antarctica from northern areas. Skates are the only group of fishes known to have survived the Oligocene cooling of Antarctica that killed or extirpated the Paleogene ichthyofauna; they persisted by a combination of cold-tolerance, generalized diet, and unspecialized bathymetric and habitat preferences.
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Priestley, Rebecca, Jacqueline Dohaney, Cliff Atkins, Rhian Salmon e Kealagh Robinson. "Engaging new Antarctic learners and ambassadors through flexible learning, open education and immersive video lectures". Polar Record 55, n. 4 (14 novembre 2018): 274–88. http://dx.doi.org/10.1017/s0032247418000384.
Testo completoAbstract (sommario):
AbstractIn April 2017, Victoria University of Wellington launched ICE101X—Antarctica: From Geology to Human History—on the global edX platform. This Massive Open Online Course, or MOOC, attracted 5735 learners from around the world, who engaged with content about Antarctic science, history, geology, and culture, primarily through video lectures filmed in Antarctica. Analysis of feedback from learners in three iterations of the course, offered between 2015 and 2017 and culminating in ICE101X, revealed that learners enjoyed the immersive Antarctic field lectures and learning through a diverse set of disciplinary lenses, had some preconceptions about Antarctica that were challenged by the course content, and completed the course with a new sense of interest in and protection of Antarctica.
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Beck, Peter J. "The United Nations and Antarctica 1993: continuing controversy about the UN's role in Antarctica". Polar Record 30, n. 175 (ottobre 1994): 257–64. http://dx.doi.org/10.1017/s0032247400024517.
Testo completoAbstract (sommario):
ABSTRACTThe eleventh successive annual United Nations discussion on the ‘Question of Antarctica’ took place at the close of 1993. In November the UN First Committee, guided by two reports from the UN Secretary-General, adopted a further resolution, which was adopted in December by the General Assembly as resolution A48/80. As usual, UN members, although displaying evidence of a wider international recognition of the regime's merits, proved critical of the Antarctic Treaty System. By contrast, Antarctic Treaty Parties (ATPs) remained reluctant to allow the UN the type of role in Antarctica advocated by their critics. ATPs, following the course adopted in 1985, still refused either to participate in the UN discussions or to vote. As a result, it proved impossible yet again to secure a consensus about either the ‘Question of Antarctica’ in general or the UN's role in Antarctica in particular. One significant advance in 1993 concerned the end of demands advanced since 1985 for South Africa's exclusion from Antarctic meetings, a change prompted by the dismantlement of the apartheid regime. The ‘Question of Antarctica’ is scheduled to be placed on the UN agenda in 1994.
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Jezek, Kenneth C. "RADARSAT-1 Antarctic Mapping Project: change-detection and surface velocity campaign". Annals of Glaciology 34 (2002): 263–68. http://dx.doi.org/10.3189/172756402781818030.
Testo completoAbstract (sommario):
AbstractThe RADARSAT-1 Antarctic Mapping Project (RAMP) is a collaboration between NASA and the Canadian Space Agency to map Antarctica using synthetic aperture radar (SAR). The first Antarctic Mapping Mission (AMM-1) was successfully completed in October 1997. Data from the acquisition phase of the 1997 campaign have been used to achieve the primary goal of producing the first high-resolution SAR image map of Antarctica. The Modified Antarctic Mapping Mission (MAMM) occurred during the fall of 2000. The acquisition strategy concentrated on collecting highest- resolution RADARSAT-1 data of Antarctica’s fast glaciers for change detection and feature-retracking estimates of surface velocity. Additionally, extensive data were acquired for interferometric analysis over the entire viewable region, which extends north of 80.1˚ S latitude. This paper summarizes the goals and strategy behind MAMM. It goes on to discuss ice-sheet margin changes observed on several ice shelves around the continent. Margin changes are documented by comparing AMM-1 and MAMM data with earlier datasets including European Remote-sensing Satellite-1 SAR imagery, Landsat imagery, the Antarctic Digital Database (version 1) coastline and Declassified Intelligence Satellite Photography. Analysis reveals a complex pattern of ice-margin advance and retreat without indicating any systematic behavior in ice-sheet extent about the ice-sheet perimeter.
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OTT, Sieglinde. "Early stages of development in Usnea antarctica Du Rietz in the South Shetland Islands, northern maritime Antarctica". Lichenologist 36, n. 6 (novembre 2004): 413–23. http://dx.doi.org/10.1017/s0024282904014380.
Testo completoAbstract (sommario):
Juvenile development has been investigated for the first time in an Antarctic lichen species—Usnea antarctica—in the northern maritime Antarctic, Livingston Island (South Shetland Islands, 62°27′–62°48′S, 59°45′–61°15′W). Here, U. antarctica grows on rocks and forms the dominant vegetation on this site together with a few other macrolichens. This species reproduces mainly by vegetative diaspores (soredia), which include both the photobiont and the mycobiont. To understand the early ontogenetic strategies in U. antarctica, culture experiments were performed in an Antarctic field site where the species occurs naturally. This paper focuses on the different developmental steps seen between the initial colonization of soredia to the formation of a small well-developed thallus, and also on the growth rate of the respective juvenile stages. Compared with growth rates of lichens from temperate European regions the early development of U. antarctica is extraordinarily slow, taking 5–6 years until an adult thallus has been formed. The low photobiont content in the juvenile stages probably limits the growth rate. It is suggested that juvenile development of U. antarctica is controlled by a combination of ecophysiological and morphological adaptations that are required for success in extreme environments such as the terrestrial habitats of the Antarctic.
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Beck, Peter J. "Antarctica at the United Nations, 1985: the end of consensus?" Polar Record 23, n. 143 (maggio 1986): 159–66. http://dx.doi.org/10.1017/s0032247400028345.
Testo completoAbstract (sommario):
ABSTRACTThe question of Antarctica was discussed at the United Nations General Assembly in 1985 for the third successive year. While the content of the debates differed little from that of previous years, the discussions resulted in the adoption, by large majorities, of three resolutions in favour of an expanded and up-dated UN Study on Antarctica, the provision of information for the UN on the Antarctic minerals regime negotiations, and the exclusion of South Africa from the Antarctic Treaty System. The Antarctic Treaty powers, favouring no real UN role in Antarctica, stressed the need to maintain the present arrangements and did not participate in the UN votes on the three resolutions. The apparent breakdown of the consensus approach that was characteristic of 1983 and 1984 raises a question for the future; will 1986 witness bridge-building or continuing divisions on the most appropriate way to manage Antarctica in the future?
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TURCHETTI, SIMONE, KATRINA DEAN, SIMON NAYLOR e MARTIN SIEGERT. "Accidents and opportunities: a history of the radio echo-sounding of Antarctica, 1958–79". British Journal for the History of Science 41, n. 3 (9 giugno 2008): 417–44. http://dx.doi.org/10.1017/s0007087408000903.
Testo completoAbstract (sommario):
AbstractThis paper explores the history of radio echo-sounding (RES), a technique of glaciological surveying that from the late 1960s has been used to examine Antarctica's sub-glacial morphology. Although the origins of RES can be traced back to two accidental findings, its development relied upon the establishment of new geopolitical conditions, which in the 1960s typified Antarctica as a continent devoted to scientific exploration. These conditions extended the influence of prominent glaciologists promoting RES and helped them gather sufficient support to test its efficiency. The organization and implementation of a large-scale research programme of RES in Antarctica followed these developments. The paper also examines the deployment of RES in Antarctic explorations, showing that its completion depended on the availability of technological systems of which RES was an integral part.
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Gil-Delgado, J. A., J. González-Solís e A. Barbosa. "Populations of breeding birds in Byers Peninsula, Livingston Island, South Shetland Islands". Antarctic Science 25, n. 2 (20 marzo 2013): 303–6. http://dx.doi.org/10.1017/s0954102012000752.
Testo completoAbstract (sommario):
AbstractData about breeding populations of birds in the Antarctica are rare and fragmented. Thus, information about the status of the breeding populations of Antarctic birds is crucial given the current scenario of climate change, which is particularly acute in Antarctica. This paper presents new information about the populations of the Antarctic tern Sterna vittata, the kelp gull Larus dominicanus, the southern giant petrel Macronectes giganteus, the Antarctic skua Catharacta antarctica lonnbergi, the chinstrap penguin Pygoscelis antarctica and the gentoo penguin Pygoscelis papua on Byers Peninsula (Livingston Island, South Shetland Islands). We used line transects counts to estimate both densities and numbers of nests of the different species. We estimate that there are 398.96 birds km-2 of southern giant petrels (2793 individuals), 62.4 birds km-2 of Antarctic tern (3746 individuals) and 269.1 birds km-2 of kelp gull (1884 individuals). Furthermore, we found 15 nests of Antarctic skua in 25 km2, from which we can estimate that 60–91 birds must breed on Byers Peninsula. We also censused two colonies of gentoo penguins (3000 and 1200 pairs) and 50 pairs of chinstrap. Compared to previous estimates, gentoo penguins seem to have increased whereas chinstrap penguin have decreased. Finally, the populations of Antarctic tern, southern giant petrel and kelp gull have stabilized or slightly increased.