Добірка наукової літератури з теми "Heard Island (Heard and McDonald Islands)"

The McDonald Islands (53°S, 73°E) originally comprised three small islands that lie on the Kerguelen Plateau, 44 km west of Heard Island. No volcanic activity was observed since their discovery in 1874 until 1997, when two passing ships recorded major changes and eruptive behaviour. A 2001 satellite image showed that the main island had doubled its area. This paper reports observations made from a cruise ship in November 2002, supplemented by a high-resolution satellite image acquired in March 2003. A new volcanic complex comprises lava domes, spines and flows, all assumed to be phonolitic, similar to the older volcanic rocks. The complex shows dormant volcanic activity, with numerous fumaroles, recent spine evolution and lava flows. Changes in relative sea level have connected Flat and McDonald Islands. A spit about 1km long with extensive shoals beyond, now extends eastward from McDonald Island and presents new hazards to shipping. Biological changes include colonization by king penguins (Aptenodytes patagonica), previously absent, and a large reduction in numbers of formerly widespread macaroni penguins (Eudyptes chrysolophus chrysolophus).

In 1947 knowledge of Heard Island was confined to a rough mapping compiled by nineteenth-century sealers, and the results of four scientific expeditions that had briefly investigated the Atlas Cove area. Exploration continued in two distinct periods between 1947 and 1971. In the first period the Australian National Antarctic Research Expeditions (ANARE) built a scientific station at Atlas Cove in 1947, and occupied it continuously until 1955 as an ‘A Class’ meteorological station, a seismic and magnetic observatory, and a base for other scientific studies and for exploration of the island. In the second period four summer expeditions and one wintering expedition worked on the island between 1963 and 1971. The summer expeditions were an ANARE expedition in 1963, an Australian private expedition (The South Indian Ocean Expedition to Heard Island) in 1965, and ANARE expeditions in 1969 and 1971 associated with United States and French expeditions. A United States expedition wintered in 1969. There were no further expeditions until 1980. The years 1947–1971 saw many achievements. Expedition members recorded seven years of synoptic meteorological observations and four years of seismic and magnetic observations. They developed empirical techniques of work, travel, and survival that shaped the collective character of ANARE and were later applied in Antarctica. Despite difficult terrain and consistently bad weather, and the accidental deaths of two men in 1952, unsupported field parties of two or three men travelling on foot explored and mapped in detail the heavily glaciated island, and documented its topography, geology, glaciology and biology. They made three overland circuits of the island, the first ascent of Big Ben (2745 m), and the first recorded landing on the nearby McDonald Islands. Expedition members bred and trained dog teams for later use in Antarctica. They reported the commencement and subsequent progress of massive glacier retreat caused by regional warming, and of the island's colonisation by king penguins (Aptenodytes patagonicus) and antarctic fur seals (Arctocephalus gazella). They also reported measurements of glacier flow and thickness, the palaeomagnetism of Heard Island rocks, behavioural and population studies of southern giant petrels (Macronectes giganteus) and other birds, studies of southern elephant seals (Mirounga leonina) and leopard seals (Hydrurga leptonyx), and the cold stress and acclimatisation experienced by humans working in the island's wet-cold climate. In addition, Heard Island served as a testing ground for men, equipment, scientific programmes, huskies, general administration, and logistics, without which Mawson station could not have been established as successfully as it was in 1954. The American wintering expedition and the French summer expedition contributed to major international geodetic and geophysical investigations. In sum, the expeditions between 1947 and 1971 added much to our knowledge of Heard Island, and they laid down a solid foundation for the work of later expeditions.

Two mitochondrial DNA regions and seven microsatellite loci were examined in Patagonian toothfish from three locations in the Southern Ocean (Macquarie Island, five collections; Heard and McDonald Islands, four collections; Shag Rocks/South Georgia area, one collection). Striking mtDNA heterogeneity was detected between the three fishing locations (FST=0.445, P<0.001), but spatial and temporal collections within the same location were not significantly different. No significant overall microsatellite differentiation between the three locations was apparent (FST=−0.009, P=0.785). However, some individual loci showed small but significant differentiation, which in each case was attributable to between rather than within-location differentiation. Greater differentiation of mtDNA can, in principle, be explained either by female philopatry and male dispersal, or by its greater sensitivity to changes in effective population size. The latter seems more likely as tagging indicates that toothfish is generally a sedentary species. The genetic heterogeneity between the three locations indicates restricted gene flow, with the fish at each location comprising independent units. Depletion in one location is therefore unlikely to be quickly replaced by immigration from another.

AbstractOf the more than twenty historically active volcanoes in Antarctica and the sub-Antarctic region only two, to our knowledge, host any ground-based monitoring instruments. Moreover, because of their remoteness, most of the volcanoes are seldom visited, thus relegating the monitoring of volcanism in this region almost entirely to satellites. In this study, high temporal resolution satellite data from the Hawaii Institute of Geophysics and Planetology's MODVOLC system using MODIS (Moderate Resolution Imaging Spectroradiometer) are complemented with high spatial resolution data (ASTER, or Advanced Spaceborne Thermal Emission and Reflection Radiometer, and similar sensors) to document volcanic activity throughout the region during the period 2000–10. Five volcanoes were observed in eruption (Mount Erebus, Mount Belinda, Mount Michael, Heard Island and McDonald Island), which were predominantly low-level and effusive in nature. Mount Belinda produced tephra, building a cinder cone in addition to an extensive lava field. Five volcanoes exhibited detectable thermal, and presumed fumarolic, activity (Deception, Zavodovski, Candlemas, Bristol, and Bellingshausen islands). A minor eruption reported at Marion Island was not detected in our survey due to its small size. This study also discovered a new active vent on Mount Michael, tracked dramatic vent enlargement on Heard Island, and provides an improved picture of the morphology of some of the volcanoes.

Abstract In 2016, the South China Sea Arbitral Tribunal was the first tribunal or court to interpret Article 121(3) of the United Nations Convention on the Law of the Sea. The Tribunal’s interpretation raises international law questions regarding the validity of claimed exclusive economic zones (eezs) and continental shelf maritime areas around many islands including Australia’s sub-Antarctic Islands. Owing to their geographical remoteness, harsh climates, lack of resources, as well as never been ‘home’ to any group of people in a settled way, questions have been raised as to the validity of Australia’s claimed maritime zones with respect to Article 121(3) in both pre- and post-South China Sea Arbitral Award commentary. The article assesses the validity of Australia’s claim by applying the Tribunal’s interpretation of Article 121(3) to the physical and historical facts of the Islands while raising alternate interpretations offered by prior and subsequent commentary. Three examples of possible State practice are reviewed for evidence of other interpretations that may have been agreed to by parties to the Convention. The findings are that Heard and Macquarie Islands are likely classified as islands entitled to an eez and continental shelf whereas McDonald Island is more likely to be an Article 121 ‘rock’.

The known distribution of Macrourus caml is extended to the Ob and Lena Banks area, and southwest of Heard and McDonald Islands. Macrourus holotrachys was recorded from Prince Edward Islands and the Ob and Lena Banks. Macrourus carinatus specimens examined were all from Prince Edward Islands, the type locality. Macrourus whitsoni specimens examined were all from the southeast Atlantic Ocean at about 69˚S, close to the Antarctic continent (off Maud Land), consistent with a previous study which reported the species from 64–77˚S. A revised identification key is provided.

Heard Island is located in one of the more isolated regions of the southern Indian Ocean at 53°06' S 73°30 E. There are 29 glacerised basins on Heard Island, which cover 70% of this 367 km2 island. Changes in the positions of Heard Island's glaciers, and by inference, changes in the region's climate, have been recorded only intermittently since the establishment of the first Australian base in 1947. In the 1950s the majority of these glaciers were stable or slightly thinning until a marked retreat began in the early 1960s. The retreat from the 1960s has continued through the last recorded observation in 2004. As of 1997, the glaciers on Heard Island had a total area of 257 km2 and an estimated volume of 14.2 km3. The limited climate records for the southern Indian Ocean have shown that there has been a +0.9° C (or +1.7° C 100a-1) change in temperature on Heard Island between 1947 and 2006, with similar increases in temperatures on the other sub-Antarctic islands (e. g., +2.7° C 100a-1 at Marion, +1.0° C 100a-1 at Kerguelen and +1.4° C 100a-1 at New Amsterdam islands). Additionally there has been a decrease in precipitation at Marion Island and Kerguelen since the late 1960s. The changes in air temperature and precipitation in the southern Indian Ocean over the last 60 years has had a significant effect of the glacier coverage on the region's islands. There have been dramatic changes in the extent of several glaciers observed on Marion, Crozet, Bouvetoya, and Kerguelen. The glaciers and semi-permanent snow cover on the more northern Marion and Crozet islands have disappeared completely since these islands were first discovered. Kerguelen Island glaciers have decreased in extent, with one of the original five regions disappearing completely. The limited observations on Bouvetoya indicates there has been only minor changes in it's glacier fronts. There are few observations of glacier front changes and even fewer glacier mass balance measurements on Heard Island. The changes in glacier front and climate for Brown Glacier, located on the northeastern coast of Heard Island, was determined by combining the climatic and physical characteristics that are measured on Heard Island, from 1950 to present. Ice core and crevasse samples were collected on Brown Glacier, on the northeast coast, in 2004 to determine the net balance from stratigraphic data and glaciochemical analysis. Oxygen isotope and trace ion were measured from ice cores and crevasses to observe any seasonal signals present in the ice and thereby determining the net balance. Although meltwater affected some of the sample sites a comparison with a low melt location, at 2450 m asl, reveals that melt effects are very site specific. Two non-melt affected sites, at elevations of 756 m and 920 m, provide an estimated net balance of 1.5 m w.e. Ablation was estimated from a combination of stake networks, downward looking sonars and a degree day model. A twenty stake central flowline network and downward looking sonars were deployed on Brown Glacier during the summers of 2000/01 and 2003/04 to measure the changes in the surface height. These measurements were compared to a degree day model for the ablation over the same period. The results indicated that in remote areas, degree day models can provide good estimates of the ablation when limited energy balance variables are available. The mass balance models for Brown Glacier indicate that an increase in temperature of 0.9° C between 1950 and 2001, and possibly a decrease in precipitation, has resulted in the retreat of the glacier. The steady state mass flux for 2001 indicates that if all of the current parameters remained constant then the terminus of Brown Glacier will retreat to an elevation of 350m. IPCC projections for 2090 were used to predict the changes that would occur on Brown Glacier if there was a further increase of temperature of 1.8 and 3.4° C. In both of these models Brown Glacier would cease to exist or possibly retreat to a small, semi-permanent snow field. This has similar implications for the other glaciers on Heard Island. Further increases in temperature and a continuation of the decreasing precipitation trends observed on the neighbouring sub-Antarctic islands implies that the smaller glaciers on Heard Island would also begin to retreat at a more rapid rate over the next 90 years. Glacier such as the Mary Powell, Nares, and Deacock that do not originate from high on the Big Ben Plateau are likely to retreat to elevation above —1000 m asl and the glaciers on the Laurens Peninsula will have disappeared completely.

Australia is the custodian of a diverse range of continental and oceanic islands. From Heard and Macquarie in the sub-Antarctic, to temperate Lord Howe and Norfolk, to the tropical Cocos (Keeling) Islands and the islands of the Great Barrier Reef, Australia’s islands contain some of the nation’s most iconic fauna, flora and ecosystems. They are a refuge for over 35% of Australia’s threatened species and for many others declining on mainland Australia. They also have significant cultural value, especially for Indigenous communities, and economic value as centres for tourism. Australian Island Arks presents a compelling case for restoring and managing islands to conserve our natural heritage. With contributions from island practitioners, researchers and policy-makers, it reviews current island management practices and discusses the need and options for future conservation work. Chapters focus on the management of invasive species, threatened species recovery, conservation planning, Indigenous cultural values and partnerships, tourism enterprises, visitor management, and policy and legislature. Case studies show how island restoration and conservation approaches are working in Australia and what the emerging themes are for the future. Australian Island Arks will help island communities, managers, visitors and decision-makers to understand the current status of Australia’s islands, their management challenges, and the opportunities that exist to make best use of these iconic landscapes.

Many people today have never heard of the Comoros, but these islands were once part of a prosperous economic system that stretched halfway around the world. A key node in the trading networks of the Indian Ocean, the Comoros thrived by exchanging slaves and commodities with African, Arab and Indian merchants. By the seventeenth century, the archipelago had become an important supply point on the route from Europe to Asia, and developed a special relationship with the English. The twentieth century brought French colonial rule and a plantation economy based on perfumes and spices. In 1975, following decades of neglect, the Comoros declared independence from France, only to be blighted by a series of coups, a radical revolutionary government and a mercenary regime. Today, the island nation suffers chronic mismanagement and relies on foreign aid and remittances from a diasporic community in France. Nonetheless, the Comoros are largely peaceful and culturally vibrant—connected to the outside world in the internet age, but, at the same time, still slightly apart. Iain Walker traces the history and unique culture of these enigmatic islands, from their first settlement by Africans, Arabs and Austronesians, through their heyday within the greater Swahili world and their decline as a forgotten outpost of the French colonial empire, to their contemporary status as an independent state in the Indian Ocean.

Possibly the most successful urban birds, pigeons and doves in the Order Columbiformes are one of the most easily recognised groups. They are an ancient and very successful group with an almost worldwide distribution and are most strongly represented in tropical and subtropical regions, including Australia. In most species simple plumage patterns feature mainly grey and brown with black, white or dull reddish markings, but the highly colourful fruit-doves include some of the most beautiful of all birds. From dense rainforests of north Queensland, where brilliantly plumaged Superb Fruit-Doves Ptilinopus superbus are heard more easily than seen, to cold, windswept heathlands of Tasmania, where Brush Bronzewings Phaps elegans are locally common, most regions of Australia are frequented by one or more species. For more than a century after arrival of the First Fleet, interest in these birds focused on the eating qualities of larger species. In addition to contributing to declines of local populations in some parts of Australia, excessive hunting brought about the extinction of two species on Lord Howe Island and another species on Norfolk Island. In Pigeons and Doves in Australia, Joseph Forshaw and William Cooper have summarised our current knowledge of all species, including those occurring on Christmas, Norfolk and Lord Howe Islands, and with superb artwork have given readers a visual appreciation of the birds in their natural habitats. Historical accounts of extinct species are also included. Detailed information on management practices for all species is presented, ensuring that Pigeons and Doves in Australia will become the standard reference work on these birds for ornithologists and aviculturists. Winner of a 2015 Whitley Awards Certificate of Commendation for Illustrated Text.