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Horrocks Block
Horrocks Block () is a large rectangular outcrop that is composed mainly of sandstone, lying on the north side of Venus Glacier, southwest of the Keystone Cliffs, on the east side of Alexander Island, Antarctica. It was 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 was named by the UK Antarctic Place-Names Committee from association with Venus Glacier after Jeremiah Horrocks, the British astronomer who predicted and first observed a transit of Venus frameless, upright=0.5 A transit of Venus across the Sun takes place when the planet Venus passes directly between the Sun and a superior planet, becoming visible against (and hence obscuring a small portion of) the solar disk. During a trans ..., in 1639. Horrocks Block seems to have some relation with nearby Bandstone Block, they appear to be both large rectangular outcrops of sandsto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandstone
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) because they are the most resistant minerals to weathering processes at the Earth's surface. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Since sandstone beds often form highly visible cliffs and other topographic features, certain colors of sandstone have been strongly identified with certain regions. Rock formations that are primarily composed of sandstone usually allow the percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Quartz-bearing sandstone can be changed into quartzite through metamorphism, usually related to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venus Glacier
Venus Glacier () is a glacier on the east coast of Alexander Island, Antarctica, 10 nautical miles (18 km) long and 6 nautical miles (11 km) wide at its mouth flowing east into George VI Sound lying between Keystone Cliffs and Triton Point. The coast in this vicinity was first seen from the air by Lincoln Ellsworth on November 23, 1935 and roughly mapped from photos obtained on that flight by W.L.G. Joerg. The glacier was first surveyed in 1949 by the Falkland Islands Dependencies Survey and named by the United Kingdom Antarctic Place-Names Committee for the planet Venus, the second planet of the Solar System. See also * List of glaciers in the Antarctic * Jupiter Glacier * Pluto Glacier * Uranus Glacier Further reading * J.L. SMELLIE, Lithostratigraphy of Miocene-Recent, alkaline volcanic fields in the Antarctic Peninsula and eastern Ellsworth Land', Antarctic Science 71 (3): 362-378 (1999) External links Venus Glacieron USGS website Venus Glacieron SCAR ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keystone Cliffs
The Keystone Cliffs () are a set of cliffs, high, marking the east face of the sedimentary ridge between Mercury Glacier and Venus Glacier, on the east coast of Alexander Island, Antarctica. The coast in this vicinity was first seen from the air by Lincoln Ellsworth on November 23, 1935, and roughly mapped from photos obtained on that flight by W.L.G. Joerg. The cliffs were roughly surveyed in 1936 by the British Graham Land Expedition and resurveyed in 1948 by the Falkland Islands Dependencies Survey (FIDS). They were so named by the FIDS because the geologic structures revealed in these cliffs provided the key to the general tectonic structure of the area. See also * Cannonball Cliffs * Corner Cliffs * Two Step Cliffs Two Step Cliffs () is the eastern face of a flat-topped sedimentary mountain, rising to about 680 m, immediately east of Mars Glacier on the east coast of Alexander Island, Antarctica. At the bottom of the cliffs is the Two Step Moraine. First ... Referen ... [...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] |
Directorate Of Overseas Surveys
The Ordnance Survey International or Ordnance Survey Overseas Directorate its predecessors built an archive of air photography, map and survey records for the United Kingdom from 1946 to 1999. The Ordnance Survey International Collection (formerly the Ordnance Survey International Library) held mapping records that were acquired outside the UK. Although the international division opened in 1946, the OS had been involved in overseas work for almost a century (notably the 1864-65 Ordnance Survey of Jerusalem). The agency was closed in 2001. History The agency In 1946 the ''Directorate of Colonial Surveys'' (DCS) was established by the Colonial Office to provide a central survey and mapping organisation for British colonies and protectorates. In 1957, with the imminent decolonisation of many British territories, it was renamed the ''Directorate of Overseas Surveys'' (DOS). Government reviews during the 1970s led to it being merging into the Ordnance Survey (OS) in 1984 whence it was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Aeronautics And Space Administration
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding the National Advisory Committee for Aeronautics (NACA), to give the U.S. space development effort a distinctly civilian orientation, emphasizing peaceful applications in space science. NASA has since led most American space exploration, including Project Mercury, Project Gemini, the 1968-1972 Apollo Moon landing missions, the Skylab space station, and the Space Shuttle. NASA supports the International Space Station and oversees the development of the Orion spacecraft and the Space Launch System for the crewed lunar Artemis program, Commercial Crew spacecraft, and the planned Lunar Gateway space station. The agency is also responsible for the Launch Services Program, which provides oversight of launch operations and countdown management for ... [...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] |
Jeremiah Horrocks
Jeremiah Horrocks (16183 January 1641), sometimes given as Jeremiah Horrox (the Latinised version that he used on the Emmanuel College register and in his Latin manuscripts), – See footnote 1 was an English astronomer. He was the first person to demonstrate that the Moon moved around the Earth in an elliptical orbit; and he was the only person to predict the transit of Venus of 1639, an event which he and his friend William Crabtree were the only two people to observe and record. Most remarkably, Horrocks (correctly) asserted that Jupiter was accelerating in its orbit while Saturn was slowing and interpreted this as due to mutual gravitational interaction, thereby demonstrating that gravity's actions were not limited to the Earth, Sun, and Moon. His early death and the chaos of the English Civil War nearly resulted in the loss to science of his treatise on the transit, ''Venus in sole visa''; but for this and his other work he is acknowledged as one of the founding fathers o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transit Of Venus
frameless, upright=0.5 A transit of Venus across the Sun takes place when the planet Venus passes directly between the Sun and a superior planet, becoming visible against (and hence obscuring a small portion of) the solar disk. During a transit, Venus can be seen from Earth as a small black dot moving across the face of the Sun. The duration of such transits is usually several hours (the transit of 2012 lasted 6 hours and 40 minutes). A transit is similar to a solar eclipse by the Moon. While the diameter of Venus is more than three times that of the Moon, Venus appears smaller, and travels more slowly across the face of the Sun, because it is much farther away from Earth. Transits of Venus are among the rarest of predictable astronomical phenomena. They occur in a pattern that generally repeats every 243 years, with pairs of transits eight years apart separated by long gaps of 121.5 years and 105.5 years. The periodicity is a reflection of the fact that the orbital periods ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bandstone Block
Bandstone Block () is an almost rectangular block of sandstone in eastern Alexander Island, Antarctica. It rises to about north of Triton Point at the mouth of Venus Glacier. The coast in this vicinity was first seen from the air by Lincoln Ellsworth on November 23, 1935, and roughly mapped from photos obtained on that flight by W.L.G. Joerg. This feature was first surveyed in 1949 by the Falkland Islands Dependencies Survey, who named it because of its conspicuous sedimentary bands. See also * Horrocks Block Horrocks Block () is a large rectangular outcrop that is composed mainly of sandstone, lying on the north side of Venus Glacier, southwest of the Keystone Cliffs, on the east side of Alexander Island, Antarctica. It was mapped by the Directorat ... * Rhea Corner References Rock formations on Alexander Island {{AlexanderIsland-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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