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Geode Nunataks
The Geode Nunataks () are a group of small nunataks on the west side of Sibelius Glacier, immediately north of the northern extremity of the Finlandia Foothills, in northeast Alexander Island, Antarctica. They were so named by the UK Antarctic Place-Names Committee in 1977; the nunataks are composed of lava flows with abundant geodes (cavities within the rock containing quartz and calcite crystals). See also * Appalachia Nunataks * Ceres Nunataks * Gannon Nunataks The Gannon Nunataks () are a notable twin-peaked group of nunataks (about high) and several smaller rock outcrops, located between the northern end of the LeMay Range and the Lully Foothills, situated in the west-central portion of Alexander Is ... References Nunataks of Alexander Island {{AlexanderIsland-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nunatak
A nunatak (from Inuit ''nunataq'') is the summit or ridge of a mountain that protrudes from an ice field or glacier that otherwise covers most of the mountain or ridge. They are also called glacial islands. Examples are natural pyramidal peaks. When rounded by glacial action, smaller rock promontories may be referred to as rognons. The word is of Greenlandic origin and has been used in English since the 1870s. Description The term is typically used in areas where a permanent ice sheet is present and the nunataks protrude above the sheet.J. J. Zeeberg, ''Climate and Glacial History of the Novaya Zemlya Archipelago, Russian Arctic''. pp. 82–84 Nunataks present readily identifiable landmark reference points in glaciers or ice caps and are often named. While some nunataks are isolated, sometimes they form dense clusters, such as Queen Louise Land in Greenland. Nunataks are generally angular and jagged, which hampers the formation of glacial ice on their tops, although snow can a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sibelius Glacier
Sibelius Glacier () is a glacier, 12 miles (19 km) long and 6 miles (10 km) wide, flowing south into the Mozart Ice Piedmont 10 miles (16 km) southwest of Mount Stephenson in the northern portion of Alexander Island, Antarctica. The glacier was first sighted from the air by the British Graham Land Expedition in 1937. Mapped from air photos taken by the Ronne Antarctic Research Expedition in 1947–48, by Searle of the Falkland Islands Dependencies Survey in 1960. This feature was named by the United Kingdom Antarctic Place-Names Committee for Jean Sibelius (1865-1957), Finnish composer. See also * List of glaciers in the Antarctic There are many glaciers in the Antarctic. This set of lists does not include ice sheets, ice caps or ice fields, such as the Antarctic ice sheet, but includes glacial features that are defined by their flow, rather than general bodies of ice. Th ... * Bartók Glacier * Gilbert Glacier * Paulus Glacier Glaciers of Alexander ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Finlandia Foothills
The Finlandia Foothills () are a rock massif, long and wide, rising to about at the west side of Sibelius Glacier, situated in northern Alexander Island, Antarctica. The massif lies immediately south of the Geode Nunataks, north of the Handel Ice Piedmont and west of Witches Cauldron. They were photographed from the air by the Ronne Antarctic Research Expedition, 1947–48, and mapped from these photographs by D. Searle of the Falkland Islands Dependencies Survey, 1960. In association with the glacier they were named after the symphonic poem ''Finlandia'' by the Finnish composer Jean Sibelius Jean Sibelius ( ; ; born Johan Julius Christian Sibelius; 8 December 186520 September 1957) was a Finnish composer of the late Romantic and 20th-century classical music, early-modern periods. He is widely regarded as his country's greatest com ... (1865-1957). References Mountains of Alexander Island Jean Sibelius {{AlexanderIsland-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexander Island
Alexander Island, which is also known as Alexander I Island, Alexander I Land, Alexander Land, Alexander I Archipelago, and Zemlja Alexandra I, is the largest island of Antarctica. It lies in the Bellingshausen Sea west of Palmer Land, Antarctic Peninsula from which it is separated by Marguerite Bay and George VI Sound. The George VI Ice Shelf entirely fills George VI Sound and connects Alexander Island to Palmer Land. The island partly surrounds Wilkins Sound, which lies to its west.Stewart, J. (2011) ''Antarctic An Encyclopedia'' McFarland & Company Inc, New York. 1776 pp. . Alexander Island is about long in a north–south direction, wide in the north, and wide in the south. Alexander Island is the second-largest uninhabited island in the world, after Devon Island. History Alexander Island was discovered on January 28, 1821, by a Russian expedition under Fabian Gottlieb von Bellingshausen, who named it Alexander I Land for the reigning Tsar Alexander I of Russia. Wha ... [...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] |
UK Antarctic Place-Names Committee
The UK Antarctic Place-Names Committee (or UK-APC) is a United Kingdom government committee, part of the Foreign and Commonwealth Office, responsible for recommending names of geographical locations within the British Antarctic Territory (BAT) and the South Georgia and the South Sandwich Islands (SGSSI). Such names are formally approved by the Commissioners of the BAT and SGSSI respectively, and published in the BAT Gazetteer and the SGSSI Gazetteer maintained by the Committee. The BAT names are also published in the international Composite Gazetteer of Antarctica maintained by Scientific Committee on Antarctic Research, SCAR. The Committee may also consider proposals for new place names for geographical features in areas of Antarctica outside BAT and SGSSI, which are referred to other Antarctic place-naming authorities, or decided by the Committee itself if situated in the unclaimed sector of Antarctica. Names attributed by the committee * Anvil Crag, named for descriptive featu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or underwater, usually at temperatures from . The volcanic rock resulting from subsequent cooling is also often called ''lava''. A lava flow is an outpouring of lava during an effusive eruption. (An explosive eruption, by contrast, produces a mixture of volcanic ash and other fragments called tephra, not lava flows.) The viscosity of most lava is about that of ketchup, roughly 10,000 to 100,000 times that of water. Even so, lava can flow great distances before cooling causes it to solidify, because lava exposed to air quickly develops a solid crust that insulates the remaining liquid lava, helping to keep it hot and inviscid enough to continue flowing. The word ''lava'' comes from Italian and is probably derived from the Latin word ''labes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geode
A geode (; ) is a geological secondary formation within sedimentary and volcanic rocks. Geodes are hollow, vaguely spherical rocks, in which masses of mineral matter (which may include crystals) are secluded. The crystals are formed by the filling of vesicles in volcanic and subvolcanic rocks by minerals deposited from hydrothermal fluids; or by the dissolution of syn-genetic concretions and partial filling by the same or other minerals precipitated from water, groundwater, or hydrothermal fluids. Formation Geodes can form in any cavity, but the term is usually reserved for more or less rounded formations in igneous and sedimentary rocks. They can form in gas bubbles in igneous rocks, such as vesicles in basaltic lava; or, as in the American Midwest, in rounded cavities in sedimentary formations. After rock around the cavity hardens, dissolved silicates and/or carbonates are deposited on the inside surface. Over time, this slow feed of mineral constituents from groundwater o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartz
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar. Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation from α-quartz to β-quartz takes place abruptly at . Since the transformation is accompanied by a significant change in volume, it can easily induce microfracturing of ceramics or rocks passing through this temperature threshold. There are many different varieties of quartz, several of which are classified as gemstones. Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Eurasia. Quartz is the mineral defining the val ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcite
Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on the Mohs scale of mineral hardness, based on Scratch hardness, scratch hardness comparison. Large calcite crystals are used in optical equipment, and limestone composed mostly of calcite has numerous uses. Other polymorphs of calcium carbonate are the minerals aragonite and vaterite. Aragonite will change to calcite over timescales of days or less at temperatures exceeding 300 °C, and vaterite is even less stable. Etymology Calcite is derived from the German ''Calcit'', a term from the 19th century that came from the Latin word for Lime (material), lime, ''calx'' (genitive calcis) with the suffix "-ite" used to name minerals. It is thus etymologically related to chalk. When applied by archaeology, archaeologists and stone trade pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Appalachia Nunataks
The Appalachia Nunataks () are a group of nunataks rising to about on the west side of the Elgar Uplands, Alexander Island, Antarctica. They are situated 5.62 km southwest of Lyubimets Nunatak, 9 km southwest of Kozhuh Peak and 9.65 km north of Atanasov Ridge, and surmount Nichols Snowfield to the west. The feature was named by the United Kingdom Antarctic Place-Names Committee in 1977 after ''Appalachia'', the 1902 Frederick Delius Delius, photographed in 1907 Frederick Theodore Albert Delius ( 29 January 1862 – 10 June 1934), originally Fritz Delius, was an English composer. Born in Bradford in the north of England to a prosperous mercantile family, he resisted atte ... composition, in association with Delius Glacier and the names of composers in this area. References * Nunataks of Alexander Island {{AlexanderIsland-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceres Nunataks
The Ceres Nunataks () are a group of three nunataks located immediately east of the base of Shostakovich Peninsula in southern Alexander Island, Antarctica. They were mapped by the Directorate of Overseas Surveys from satellite imagery supplied by the U.S. National Aeronautics and Space Administration in cooperation with the U.S. Geological Survey, and named by the UK Antarctic Place-Names Committee after Ceres, one of the asteroids lying between the orbits of the planets Mars and Jupiter. Geology According to the British Antarctic Survey's (BAS) aeromagnetic 1975 survey of Ceres Nunataks and nearby Astraea Nunatak, this geographical feature is rich in the igneous rocks Diorite and Tonalite as presumed by the rock samples which were observed by BAS during this survey. Aeromagnetic Survey of Ceres Nunataks and Astraea Nunatak In December 1975, the British Antarctic Survey (BAS) (originally known as the Falkland Islands Dependencies Survey (FIDS)) embarked on an 8-week long sur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
