|
Alcyone Cone
The Pleiades are a volcanic group in northern Victoria Land of Antarctica. It consists of youthful cones and domes with Mount Atlas/Mount Pleiones, a small stratovolcano formed by three overlapping cones, being the dominant volcano and rising above the Evans Névé plateau. Two other named cones are Alcyone Cone and Taygete Cone, the latter of which has been radiometrically dated to have erupted during the Holocene. A number of tephra layers across Antarctica have been attributed to eruptions of this volcanic group, including several that may have occurred within the last few hundred years. Geography and geomorphology The Pleiades are located at the crest of the Transantarctic Mountains,Stump 1986, p.305 Kyle 1982, p.747Faure and Mensing 2011, p.549 away from the coast of Lady Newnes Bay, Ross Sea.Kyle 1982, p.748 The volcanoes are located between Evans Neve and the beginning of Mariner Glacier, which drains Evans Neve southeastwards towards the Ross Sea. The volcanic gro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Victoria Land
Victoria Land is a region in eastern Antarctica which fronts the western side of the Ross Sea and the Ross Ice Shelf, extending southward from about 70°30'S to 78°00'S, and westward from the Ross Sea to the edge of the Antarctic Plateau. It was discovered by Captain James Clark Ross in January 1841 and named after Queen Victoria. The rocky promontory of Minna Bluff is often regarded as the southernmost point of Victoria Land, and separates the Scott Coast to the north from the Hillary Coast of the Ross Dependency to the south. The region includes ranges of the Transantarctic Mountains and the McMurdo Dry Valleys (the highest point being Mount Abbott in the Northern Foothills), and the flatlands known as the Labyrinth. The Mount Melbourne is an active volcano in Victoria Land. Early explorers of Victoria Land include James Clark Ross and Douglas Mawson. In 1979, scientists discovered a group of 309 meteorites in Antarctica, some of which were found near the Allan Hills in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ross Sea
The Ross Sea is a deep bay of the Southern Ocean in Antarctica, between Victoria Land and Marie Byrd Land and within the Ross Embayment, and is the southernmost sea on Earth. It derives its name from the British explorer James Clark Ross who visited this area in 1841. To the west of the sea lies Ross Island and Victoria Land, to the east Roosevelt Island and Edward VII Peninsula in Marie Byrd Land, while the southernmost part is covered by the Ross Ice Shelf, and is about from the South Pole. Its boundaries and area have been defined by the New Zealand National Institute of Water and Atmospheric Research as having an area of . The circulation of the Ross Sea is dominated by a wind-driven ocean gyre and the flow is strongly influenced by three submarine ridges that run from southwest to northeast. The circumpolar deep water current is a relatively warm, salty and nutrient-rich water mass that flows onto the continental shelf at certain locations. The Ross Sea is covered with ice ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scree
Scree is a collection of broken rock fragments at the base of a cliff or other steep rocky mass that has accumulated through periodic rockfall. Landforms associated with these materials are often called talus deposits. Talus deposits typically have a concave upwards form, where the maximum inclination corresponds to the angle of repose of the mean debris particle size. The exact definition of scree in the primary literature is somewhat relaxed, and it often overlaps with both ''talus'' and ''colluvium''. The term ''scree'' comes from the Old Norse term for landslide, ''skriða'', while the term ''talus'' is a French word meaning a slope or embankment. In high-altitude arctic and subarctic regions, scree slopes and talus deposits are typically adjacent to hills and river valleys. These steep slopes usually originate from late-Pleistocene periglacial processes. Notable scree sites in Eastern North America include the Ice Caves at White Rocks National Recreation Area in southern Ve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moraine
A moraine is any accumulation of unconsolidated debris (regolith and rock), sometimes referred to as glacial till, that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a glacier or ice sheet. It may consist of partly rounded particles ranging in size from boulders (in which case it is often referred to as boulder clay) down to gravel and sand, in a groundmass of finely-divided clayey material sometimes called glacial flour. Lateral moraines are those formed at the side of the ice flow, and terminal moraines were formed at the foot, marking the maximum advance of the glacier. Other types of moraine include ground moraines (till-covered areas forming sheets on flat or irregular topography) and medial moraines (moraines formed where two glaciers meet). Etymology The word ''moraine'' is borrowed from French , which in turn is derived from the Savoyard Italian ("mound of earth"). ''Morena'' in this case was derived from Provenà ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scoria Cone
Scoria is a pyroclastic, highly vesicular, dark-colored volcanic rock that was ejected from a volcano as a molten blob and cooled in the air to form discrete grains or clasts.Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, eds. (2005) ''Glossary of Geology'' (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. It is typically dark in color (generally dark brown, black or purplish-red), and basaltic or andesitic in composition. Scoria is relatively low in density as a result of its numerous macroscopic ellipsoidal vesicles, but in contrast to pumice, all scoria has a specific gravity greater than 1, and sinks in water. The holes or vesicles form when gases that were dissolved in the magma come out of solution as it erupts, creating bubbles in the molten rock, some of which are frozen in place as the rock cools and solidifies. Scoria may form as part of a lava flow, typically near its surface, or as fragmental ejecta ( lapilli, blocks and bombs), for ins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scoria
Scoria is a pyroclastic, highly vesicular, dark-colored volcanic rock that was ejected from a volcano as a molten blob and cooled in the air to form discrete grains or clasts.Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, eds. (2005) ''Glossary of Geology'' (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. It is typically dark in color (generally dark brown, black or purplish-red), and basaltic or andesitic in composition. Scoria is relatively low in density as a result of its numerous macroscopic ellipsoidal vesicles, but in contrast to pumice, all scoria has a specific gravity greater than 1, and sinks in water. The holes or vesicles form when gases that were dissolved in the magma come out of solution as it erupts, creating bubbles in the molten rock, some of which are frozen in place as the rock cools and solidifies. Scoria may form as part of a lava flow, typically near its surface, or as fragmental ejecta (lapilli, blocks and bombs), for inst ... [...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] |
Dike (geology)
A dike or dyke, in Geology, geological usage, is a sheet of rock that is formed in a Fracture (geology), fracture of a pre-existing rock body. Dikes can be either Intrusive rock, magmatic or Sedimentary rock, sedimentary in origin. Magmatic dikes form when magma flows into a crack then solidifies as a sheet intrusion, either cutting across layers of rock or through a contiguous mass of rock. Clastic dikes are formed when sediment fills a pre-existing crack.Essentials of Geology, 3rd Ed, Stephen Marshak Magmatic dikes A magmatic dike is a sheet of igneous rock that cuts across older rock beds. It is formed when magma fills a fracture in the older beds and then cools and solidifies. The dike rock is usually more resistant to weathering than the surrounding rock, so that erosion exposes the dike as a natural wall or ridge. It is from these natural walls that dikes get their name. Dikes preserve a record of the fissures through which most mafic magma (fluid magma low in silica) reac ... [...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] |
New Zealand Geological Survey Antarctic Expedition
The New Zealand Geological Survey Antarctic Expedition (NZGSAE) describes a series of scientific explorations of the continent Antarctica. The expeditions were notably active throughout the 1950s and 1960s. Features named by the expeditions 1957–1958 expedition The 1957–1958 expedition went to the Ross Dependency and named the Borchgrevink Glacier. Other features named include: * Carter Ridge * Felsite Island * Halfway Nunatak * Hedgehog Island * Moraine Ridge 1958–1959 expedition * Cadwalader Beach * Cape Hodgson * Carter Ridge * Isolation Point * Mountaineer Range * Mount Aurora * Mount Hayward * Mount Henderson (White Island) * Mount Bird. 1960–1961 expedition * Deverall Island * Lonewolf Nunataks 1961–1962 expedition * Aurora Heights * The Boil * Ford Spur * Graphite Peak * Half Century Nunatak * Half Dome Nunatak * Hump Passage * Last Cache Nunatak * Lookout Dome * Montgomerie Glacier * Mount Fyfe * Mount Macdonald * Snowshoe Pass * Turret Nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taurus (constellation)
Taurus (Latin for "the Bull") is one of the constellations of the zodiac and is located in the northern celestial hemisphere. Taurus is a large and prominent constellation in the Northern Hemisphere's winter sky. It is one of the oldest constellations, dating back to the Early Bronze Age at least, when it marked the location of the Sun during the spring equinox. Its importance to the agricultural calendar influenced various bull figures in the mythologies of Ancient Sumer, Akkad, Assyria, Babylon, Egypt, Greece, and Rome. Its old astronomical symbol is (♉︎), which resembles a bull's head. A number of features exist that are of interest to astronomers. Taurus hosts two of the nearest open clusters to Earth, the Pleiades and the Hyades, both of which are visible to the naked eye. At first magnitude, the red giant Aldebaran is the brightest star in the constellation. In the northeast part of Taurus is Messier 1, more commonly known as the Crab Nebula, a supernova remnant co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star Cluster
Star clusters are large groups of stars. Two main types of star clusters can be distinguished: globular clusters are tight groups of ten thousand to millions of old stars which are gravitationally bound, while open clusters are more loosely clustered groups of stars, generally containing fewer than a few hundred members, and are often very young. Open clusters become disrupted over time by the gravitational influence of giant molecular clouds as they move through the galaxy, but cluster members will continue to move in broadly the same direction through space even though they are no longer gravitationally bound; they are then known as a stellar association, sometimes also referred to as a ''moving group''. Star clusters visible to the naked eye include the Pleiades, Hyades, and 47 Tucanae. Open cluster Open clusters are very different from globular clusters. Unlike the spherically distributed globulars, they are confined to the galactic plane, and are almost always found wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.JPG "Click for more on -> Moraine")
