|
Vega Island
Vega Island is a small island to the northwest of James Ross Island, on the Antarctic Peninsula. It is separated from James Ross Island by Herbert Sound. The island was named by Otto Nordenskjold, leader of the Swedish Antarctic Expedition (1901–04) in honour of the ship making the first voyage through the Northeast Passage, 1878-79. Vega Island is an important site for paleontology. The region is extremely rich in terrestrial and marine fossils which span the boundary of the Cretaceous and Tertiary periods, covering the point in time when dinosaurs became extinct. Fossils found on the island include hadrosaurs, plesiosaurs, and mosasaurs. Geography The island is a rare volcano type called a móberg, or tuya, which was formed by a three-stage eruption sequence below an ice cap. Stage one was a subglacial hyaloclastic eruption, which shattered the lava into glass, ash, and sand which has since weathered to yellow palagonite layers. The second phase was a lava eruption into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest continent, being about 40% larger than Europe, and has an area of . Most of Antarctica is covered by the Antarctic ice sheet, with an average thickness of . Antarctica is, on average, the coldest, driest, and windiest of the continents, and it has the highest average elevation. It is mainly a polar desert, with annual precipitation of over along the coast and far less inland. About 70% of the world's freshwater reserves are frozen in Antarctica, which, if melted, would raise global sea levels by almost . Antarctica holds the record for the lowest measured temperature on Earth, . The coastal regions can reach temperatures over in summer. Native species of animals include mites, nematodes, penguins, seals and tardigrades. Where vegetation o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mosasaurs
Mosasaurs (from Latin ''Mosa'' meaning the 'Meuse', and Greek ' meaning 'lizard') comprise a group of extinct, large marine reptiles from the Late Cretaceous. Their first fossil remains were discovered in a limestone quarry at Maastricht on the Meuse in 1764. They belong to the order Squamata, which includes lizards and snakes. Mosasaurs probably evolved from an extinct group of aquatic lizards known as aigialosaurs in the Earliest Late Cretaceous with 42 described genera. During the last 20 million years of the Cretaceous period (Turonian–Maastrichtian ages), with the extinction of the ichthyosaurs and pliosaurs, mosasaurs became the dominant marine predators. They themselves became extinct as a result of the K-Pg event at the end of the Cretaceous period, about 66 million years ago. Description Mosasaurs breathed air, were powerful swimmers, and were well-adapted to living in the warm, shallow inland seas prevalent during the Late Cretaceous period. Mosasaurs were so we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argentine Antarctica
Argentine Antarctica ( es, Antártida Argentina or Sector Antártico Argentino) is an area of Antarctica claimed by Argentina as part of its national territory. It consists of the Antarctic Peninsula and a triangular section extending to the South Pole, delimited by the 25th meridian west, 25° West and 74th meridian west, 74° West meridians and the 60th parallel south, 60° South parallel. This region overlaps the British Antarctic Territory, British and Chilean Antarctic Territory, Chilean claims in Antarctica. Argentina's Antarctic claim is based on its continued presence in the region since 1904, and the area's proximity to the South American continent. Argentina's claim to this area is subject to the Antarctic Treaty. Administratively, Argentine Antarctica is a Departments of Argentina, department of the Provinces of Argentina, province of Tierra del Fuego Province, Argentina, Tierra del Fuego, Antarctica, and South Atlantic Islands. The provincial authorities are based i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleontological Sites Of Antarctica
Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossils to classify organisms and study their interactions with each other and their environments (their paleoecology). Paleontological observations have been documented as far back as the 5th century BC. The science became established in the 18th century as a result of Georges Cuvier's work on comparative anatomy, and developed rapidly in the 19th century. The term itself originates from Greek (, "old, ancient"), (, (gen. ), "being, creature"), and (, "speech, thought, study"). Paleontology lies on the border between biology and geology, but differs from archaeology in that it excludes the study of anatomically modern humans. It now uses techniques drawn from a wide range of sciences, including biochemistry, mathematics, and engineering. Us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Territorial Claims In Antarctica
Seven sovereign states – Argentina, Australia, Chile, France, New Zealand, Norway, and the United Kingdom – have made eight territorial claims in Antarctica. These countries have tended to place their Antarctic scientific observation and study facilities within their respective claimed territories; however, a number of such facilities are located outside of the area claimed by their respective countries of operation, and countries without claims such as China, India, Italy, Pakistan, Russia, South Africa ( SANAE), Ukraine, and the United States have constructed research facilities within the areas claimed by other countries. There are overlaps among the territories claimed by Argentina, Chile, and the United Kingdom. History Spanish claims According to Argentina and Chile, the Spanish Crown had claims on Antarctica. The ''capitulación'' (governorship) granted to the conquistador Pedro Sánchez de la Hoz in 1539 by the King of Spain, Charles V, explicitly included al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scientific Committee On Antarctic Research
The Scientific Committee on Antarctic Research (SCAR) is an interdisciplinary body of the International Science Council (ISC). SCAR coordinates international scientific research efforts in Antarctica, including the Southern Ocean. SCAR's scientific work is administered through several discipline-themed ''science groups''. The organisation has observer status at, and provides independent advice to Antarctic Treaty Consultative Meetings, and also provides information to other international bodies such as the Intergovernmental Panel on Climate Change (IPCC) and the United Nations Framework Convention on Climate Change (UNFCCC). History At the International Council of Scientific Unions (ICSU)’s Antarctic meeting held in Stockholm from 9–11 September 1957, it was agreed that a committee should be created to oversee scientific research in Antarctica. At the time there were 12 nations actively conducting Antarctic research and they were each invited to nominate one delegate to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandwich Bluff
Sandwich Bluff () is a flat-topped mountain, 610 m, broken sharply at its west side by a steep dark bluff standing slightly west of center on Vega Island in the James Ross Island group. Discovered by the Swedish Antarctic Expedition The Swedish Antarctic Expedition of 1901–1903 was a scientific expedition led by Otto Nordenskjöld and Carl Anton Larsen. It was the first Swedish endeavour to Antarctica in the Heroic Age of Antarctic Exploration. Background Otto Nordensk ... under Nordenskjold, 1901–04. Charted in 1945 by the FlDS, and so named because a horizontal snow-holding band of rock breaks the western cliff giving it the appearance of a sandwich when viewed from the north. Cliffs of the James Ross Island group {{GrahamLand-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Composite Antarctic Gazetteer
The Composite Gazetteer of Antarctica (CGA) of the Scientific Committee on Antarctic Research (SCAR) is the authoritative international gazetteer containing all Antarctic toponyms published in national gazetteers, plus basic information about those names and the relevant geographical features. The Gazetteer includes also parts of the International Hydrographic Organization (IHO) General Bathymetric Chart of the Oceans (GEBCO) gazetteer for under-sea features situated south of 60° south latitude. , the overall content of the CGA amounts to 37,893 geographic names for 19,803 features including some 500 features with two or more entirely different names, contributed by the following sources: {, class="wikitable sortable" ! Country ! Names , - , United States , 13,192 , - , United Kingdom , 5,040 , - , Russia , 4,808 , - , New Zealand , 2,597 , - , Australia , 2,551 , - , Argentina , 2,545 , - , Chile , 1,866 , - , Norway , 1,706 , - , Bulgaria , 1,450 , - , G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basalt
Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial planet, rocky planet or natural satellite, moon. More than 90% of all volcanic rock on Earth is basalt. Rapid-cooling, fine-grained basalt is chemically equivalent to slow-cooling, coarse-grained gabbro. The eruption of basalt lava is observed by geologists at about 20 volcanoes per year. Basalt is also an important rock type on other planetary bodies in the Solar System. For example, the bulk of the plains of volcanism on Venus, Venus, which cover ~80% of the surface, are basaltic; the lunar mare, lunar maria are plains of flood-basaltic lava flows; and basalt is a common rock on the surface of Mars. Molten basalt lava has a low viscosity due to its relatively low silica content (between 45% and 52%), resulting in rapidly moving lava flo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breccia
Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of different origins, as indicated by the named types including sedimentary breccia, tectonic breccia, igneous breccia, impact breccia, and hydrothermal breccia. A megabreccia is a breccia composed of very large rock fragments, sometimes kilometers across, which can be formed by landslides, impact events, or caldera collapse. Types Breccia is composed of coarse rock fragments held together by cement or a fine-grained matrix. Like conglomerate, breccia contains at least 30 percent of gravel-sized particles (particles over 2mm in size), but it is distinguished from conglomerate because the rock fragments have sharp edges that have not been worn down. These indicate that the gravel was deposited very close to its source area, since otherwise th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyaloclastic
Hyaloclastite is a volcanoclastic accumulation or breccia consisting of glass (from the Greek ''hyalus'') fragments (clasts) formed by quench fragmentation of lava flow surfaces during submarine or subglacial extrusion. It occurs as thin margins on the lava flow surfaces and between pillow lavas as well as in thicker deposits, more commonly associated with explosive, volatile-rich eruptions as well as steeper topography. Hyaloclastites form during volcanic eruptions under water, under ice or where subaerial flows reach the sea or other bodies of water. It commonly has the appearance of angular flat fragments sized between a millimeter to few centimeters. The fragmentation occurs by the force of the volcanic explosion, or by thermal shock and spallation during rapid cooling. Several mineraloids are found in hyaloclastite masses. Sideromelane is a basalt glass rapidly quenched in water. It is transparent and pure, lacking the iron oxide crystals dispersed in the more commonly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
