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58th Parallel South
Following are circles of latitude between the 55th parallel south and the 80th parallel south. The 55th parallel south, crossing the southernmost point of Chile, is the last line of latitude moving southward to touch any part of any continent other than Antarctica, other than minor outlying islands. 56th parallel south The 56th parallel south is a circle of latitude that is 56 degrees south of the Earth's equatorial plane. No land lies on the parallel — it crosses nothing but ocean. At this latitude the sun is visible for 17 hours, 37 minutes during the December solstice and 6 hours, 57 minutes during the June solstice. Around the world Starting at the Prime Meridian and heading eastwards, the parallel 56° south passes through: : 57th parallel south The 57th parallel south is a circle of latitude that is 57 degrees south of the Earth's equatorial plane. No land lies on the parallel — it crosses nothing but ocean. At this latitude the sun is visible for 17 hou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctica Map
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic 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 Climate of Antarctica#Precipitation, 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 temperature recorded on Earth, lowest measured temperature on Earth, . The coastal regions can reach temperatures over in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hornos Island
Hornos Island () is a Chilean island at the southern tip of South America. The island is mostly known for being the location of Cape Horn. It is generally considered South America's southernmost island, but the Diego Ramírez Islands are farther south. The island is one of the Hermite Islands, part of the Tierra del Fuego archipelago. The Chilean Navy maintains a station on the island, consisting of a residence, utility building, chapel, and lighthouse. A short distance from the main station is a memorial, including a large sculpture featuring the silhouette of an albatross, in honour of the sailors who died while attempting to "round the Horn". The island is within the Cabo de Hornos National Park. Ecology The island is dominated by Magellanic moorlands. Exposed locations are dominated by bunch grasses and short shrubs, low to the ground to avoid wind. Short trees found only in wind protected areas. The world's southernmost tree, a ''Nothofagus betuloides'', is found on Horn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Orkney Islands
The South Orkney Islands are a group of List of Antarctic and sub-Antarctic islands, islands in the Southern Ocean, about north-east of the tip of the Antarctic Peninsula''Antarctica: Secrets of the Southern Continent'' p. 122 , David McGonigal, 2009 and south-west of South Georgia Island. They have a total area of about . The islands are claimed both by Britain (as part of the British Antarctic Territory since 1962, previously as a Falkland Islands Dependencies, Falkland Islands Dependency) and by Argentina (as part of Argentine Antarctica). Under the 1959 Antarctic Treaty, sovereignty claims are held in abeyance. Britain and Argentina both maintain bases on the islands. The Argentine base, Orcadas Base, Orcadas, established in 1904, is sited on Laurie Island. The 11 buildings ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronation Island
Coronation Island is the largest of the South Orkney Islands, long and from wide. The island extends in a general east–west direction, is mainly ice-covered and comprises numerous bays, glaciers and peaks, the highest rising to . History The island was discovered in December 1821, in the course of the joint cruise by Captain Nathaniel Palmer, an American sealer, and Captain George Powell, a British sealer. Powell named the island in honour of the coronation of George IV, who had become king of the United Kingdom in 1820. Antarctic Specially Protected Area An area of some 92 km2 of north-central Coronation Island has been designated an Antarctic Specially Protected Area (ASPA 114), mainly for use as a relatively pristine reference site for use in comparative studies with more heavily impacted sites. It extends northwards from Brisbane Heights and Wave Peak in the central mountains to the coast between Conception Point in the west to Foul Point in the east. Most o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equator
The equator is the circle of latitude that divides Earth into the Northern Hemisphere, Northern and Southern Hemisphere, Southern Hemispheres of Earth, hemispheres. It is an imaginary line located at 0 degrees latitude, about in circumference, halfway between the North Pole, North and South Pole, South poles. The term can also be used for any other celestial body that is roughly spherical. In three-dimensional space, spatial (3D) geometry, as applied in astronomy, the equator of a rotating spheroid (such as a planet) is the parallel (circle of latitude) at which latitude is defined to be 0°. It is an imaginary line on the spheroid, equidistant from its geographical pole, poles, dividing it into northern and southern hemispheres. In other words, it is the intersection of the spheroid with the plane (geometry), plane perpendicular to its axis of rotation and midway between its geographical poles. On and near the equator (on Earth), noontime sunlight appears almost directly o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bristol Island
Bristol Island is an uninhabited island in the South Sandwich Islands, an archipelago in the Southern Ocean. The island is almost entirely surrounded by ice cliffs and largely covered with ice. It features both the oldest rocks of this archipelago and an active volcano that last erupted in 2016. Geography and geomorphology Bristol Island is one of the South Sandwich Islands, which lie southeast of South Georgia in the Southern Ocean and extend over a distance of in a north–south direction. It lies about southwest of Montagu Island and is separated from Southern Thule by Forsters Passage. The first island of the South Sandwich Islands to be discovered was Freezland Rock, which was sighted on 31 January 1775 by a sailor named Freezland on James Cook's HMS ''Resolution''. Cook considered Bristol Island to be a promontory on a larger island; it was Thaddeus von Bellingshausen who in 1819 determined that Bristol was actually an island. The island is almost inaccessible ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Montagu Island
Montagu Island is the largest of the South Sandwich Islands, located in the Scotia Sea off the coast of Antarctica. Almost entirely Glacier, ice-covered with only sparse rocky outcrops, Montagu consists of a large caldera with a large parasitic cone, Mount Oceanite. Several secondary volcanic cones have formed in the caldera, including Mount Belinda. The island is rarely visited owing to the remote location, and there is only sparse vegetation. Penguins and seabirds live along the coasts. Before an eruption in 2001, which continued for several years and formed a lava delta on the northern coast, Mount Belinda was not known to have been active during the Holocene (the past 12,000 years). Geography and geomorphology Montagu Island is part of the South Sandwich Islands, a north–south trending chain of islands north of Antarctica and east of the Scotia Sea southeast of the Falklands. From north to south they include Zavodovski Island, Leskov Island, Visokoi Island, Candlemas Isl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saunders Island, South Sandwich Islands
Saunders Island is a crescent-shaped island lying between Candlemas Island and Montagu Island in the South Sandwich Islands, a British Overseas Territory in the southern Atlantic Ocean. The long Saunders is a volcanic island composed of an active stratovolcano, Mount Michael, and a cluster of pyroclastic cones on the southeastern side. Mount Michael has a lava lake in its summit crater, which is fumarolically active, and there is widespread evidence of recent eruptions across the island. The island is used as a breeding ground by many bird species, including penguins, but is barren of vegetation apart from lichens and some moss-covered patches. Most of the island is covered in ice. Geography and geology Regional Saunders Island was discovered in 1775 by James Cook from , and is part of the South Sandwich Islands in the southern Atlantic Ocean at the eastern end of the Scotia Sea. They lie about north of Antarctica and about the same distance south-east of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Candlemas Island
Candlemas Island is a small uninhabited island of the Candlemas Islands in the South Sandwich Islands. It is one of about a dozen islands that make up the South Sandwich island arc, a chain of volcanoes in the Southern Ocean that was discovered in 1775 by James Cook. The volcanism is caused by the subduction of the South American Plate beneath the Sandwich Plate. The island is remote and rarely visited due to the often hostile weather conditions, but is populated by penguins and seabirds, which form large breeding colonies. The island consists of two parts. The southeastern part is older and consists of the heavily glaciated volcanoes Mount Andromeda - with elevation the highest point of the island - and Mount Perseus, and shows no evidence of recent activity. The northwestern part features the younger scoria cone complex Lucifer Hill, which is surrounded by lava flows. Some of the lava flows may have been emplaced during the 20th century. The older rocks consist mostly of ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vindication Island
Vindication Island is a small uninhabited island of the Candlemas Islands in the South Sandwich Islands. It is one of about a dozen islands that make up the South Sandwich island arc, a chain of volcanoes in the Southern Ocean that was discovered in 1775 by James Cook. The volcanism is caused by the subduction of the South American Plate beneath the Sandwich Plate. The island has a rectangular outline and is the remnant of three mostly eroded volcanoes. The highest point of the island, Quadrant Peak, directly overlies the coast. Inland Vindication Island features a rich vegetation, consisting of lichens and mosses, while various bird and penguin species breed along the coasts. There is no evidence of recent volcanic activity. History and toponymy Vindication and Candlemas Island were both discovered on 2 February 1775 by James Cook aboard . In 1951–1952 the Argentine frigates and installed a marker on Vindication, claiming Argentine sovereignty over the island; this is t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horizontal Coordinate System
The horizontal coordinate system is a celestial coordinate system that uses the observer's local horizon as the fundamental plane to define two angles of a spherical coordinate system: altitude and ''azimuth''. Therefore, the horizontal coordinate system is sometimes called the az/el system, the alt/az system, or the alt-azimuth system, among others. In an altazimuth mount of a telescope, the instrument's two axes follow altitude and azimuth. Definition This celestial coordinate system divides the sky into two hemispheres: The upper hemisphere, where objects are above the horizon and are visible, and the lower hemisphere, where objects are below the horizon and cannot be seen, since the Earth obstructs views of them. The great circle separating the hemispheres is called the ''celestial horizon'', which is defined as the great circle on the celestial sphere whose plane is normal to the local gravity vector (the vertical direction). In practice, the horizon can be define ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nautical Twilight
Twilight is daylight illumination produced by diffuse sky radiation when the Sun is below the horizon as sunlight from the upper atmosphere is scattered in a way that illuminates both the Earth's lower atmosphere and also the Earth's surface. Twilight also may be any period when this illumination occurs, including dawn and dusk. The lower the Sun is beneath the horizon, the dimmer the sky (other factors such as atmospheric conditions being equal). When the Sun reaches 18° below the horizon, the illumination emanating from the sky is nearly zero, and evening twilight becomes nighttime. When the Sun approaches re-emergence, reaching 18° below the horizon, nighttime becomes morning twilight. Owing to its distinctive quality, primarily the absence of shadows and the appearance of objects silhouetted against the lit sky, twilight has long been popular with photographers and painters, who often refer to it as the blue hour, after the French expression . By analogy with evenin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
