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Deriba Crater
Deriba is a Pleistocene or Holocene caldera in Darfur, Sudan. Part of the volcanoes of the Marra Mountains, it lies on the Darfur dome and like the Tagabo Hills and Meidob Hills volcanism may be the product of a mantle plume. After the separation of South Sudan, the highest point of Sudan is on the margin of the caldera. The caldera lies atop a shield volcano or ash cone in the southern Marra Mountains, which developed first as a pile of basaltic lava flows and later as layers of volcanic ash and tuff, including the eruptions that formed the caldera. A large eruption occurred about 3,520 ± 100 years before present, and hot springs and fumaroles are active to the present day. Deriba contains two lakes, one in the northeastern side of the main caldera and the other in a cone in the southwestern sector of the Deriba caldera. The fresher southwestern lake is smaller but considerably deeper than the saltier northeastern lake; in the late Pleistocene the caldera was filled with a la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Countries By Highest Point
The following sortable table lists land surface elevation extremes by country or dependent territory. Topographic elevation is the vertical distance above the reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface. Table }) is a salt lake on the border between Turkmenistan and Uzbekistan which dries into salt ponds and can eventually leave a salt flat with an elevation as low as in Turkmenistan. At present, the water level of the main lake in Turkmenistan is about , with a higher lake in Uzbekistan at . , - , , Blue Hills on Providenciales , North Atlantic Ocean , - , , Unnamed location on Niulakita , South Pacific Ocean , - , , Mount Stanley ( Margherita Peak) , Albert Nile , - , , Hoverla , Kuyalnik Estuary , - , , Jabal Al Jais , Persian Gulf Gulf of Oman , - , , Ben Nevis , Holme Fen , - , , Denali , Badwater Basin , - , , Unnamed hill on Sand Island ( Johnston Atoll) , Pacific Ocean , - , ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuff
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock containing 25% to 75% ash is described as tuffaceous (for example, ''tuffaceous sandstone''). Tuff composed of sandy volcanic material can be referred to as volcanic sandstone. Tuff is a relatively soft rock, so it has been used for construction since ancient times. Because it is common in Italy, the Romans used it often for construction. The Rapa Nui people used it to make most of the ''moai'' statues on Easter Island. Tuff can be classified as either igneous or sedimentary rock. It is usually studied in the context of igneous petrology, although it is sometimes described using sedimentological terms. Tuff is often erroneously called tufa in guidebooks and in television programmes. Volcanic ash The material that is expelled in a volcanic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sink
A sink is a bowl-shaped plumbing fixture for washing hands, dishwashing, and other purposes. Sinks have a tap (faucet) that supply hot and cold water and may include a spray feature to be used for faster rinsing. They also include a drain to remove used water; this drain may itself include a strainer and/or shut-off device and an overflow-prevention device. Sinks may also have an integrated soap dispenser. Many sinks, especially in kitchens, are installed adjacent to or inside a counter. When a sink becomes clogged, a person will often resort to using a chemical drain cleaner or a plunger, though most professional plumbers will remove the clog with a ''drain auger'' (often called a "plumber's snake"). History United States The washstand was a bathroom sink made in the United States in the late 18th century.Sinks ''The Old-House Journal''; Augu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pumice
Pumice (), called pumicite in its powdered or dust form, is a volcanic rock that consists of highly vesicular rough-textured volcanic glass, which may or may not contain crystals. It is typically light-colored. Scoria is another vesicular volcanic rock that differs from pumice in having larger vesicles, thicker vesicle walls, and being dark colored and denser.Jackson, J.A., J. Mehl, and K. Neuendorf (2005) ''Glossary of Geology'' American Geological Institute, Alexandria, Virginia. 800 pp. McPhie, J., M. Doyle, and R. Allen (1993) ''Volcanic Textures A guide to the interpretation of textures in volcanic rocks'' Centre for Ore Deposit and Exploration Studies, University of Tasmania, Hobart, Tasmania..198 pp. Pumice is created when super-heated, highly pressurized rock is violently ejected from a volcano. The unusual foamy configuration of pumice happens because of simultaneous rapid cooling and rapid depressurization. The depressurization creates bubbles by lowering the solubi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obsidian
Obsidian () is a naturally occurring volcanic glass formed when lava extrusive rock, extruded from a volcano cools rapidly with minimal crystal growth. It is an igneous rock. Obsidian is produced from felsic lava, rich in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. It is commonly found within the margins of rhyolite, rhyolitic lava flows known as obsidian flows. These flows have a high content of silicon dioxide, silica, granting them a high viscosity. The high viscosity inhibits atomic diffusion, diffusion of atoms through the lava, which inhibits the first step (nucleation) in the formation of mineral crystals. Together with rapid cooling, this results in a natural glass forming from the lava. Obsidian is hard, Brittleness, brittle, and amorphous; it therefore Fracture (mineralogy)#Conchoidal fracture, fractures with sharp edges. In the past, it was used to manufacture cutting and piercing tools, and it has been used experimentally as surgic ... [...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] |
Lapilli
Lapilli is a size classification of tephra, which is material that falls out of the air during a volcanic eruption or during some meteorite impacts. ''Lapilli'' (singular: ''lapillus'') is Latin for "little stones". By definition lapilli range from in diameter. A pyroclastic particle greater than 64 mm in diameter is known as a volcanic bomb when molten, or a volcanic block when solid. Pyroclastic material with particles less than 2 mm in diameter is referred to as volcanic ash. Formation Lapilli are spheroid-, teardrop-, dumbbell- or button-shaped droplets of molten or semi-molten lava ejected from a volcanic eruption that fall to earth while still at least partially molten. These granules are not accretionary, but instead the direct result of liquid rock cooling as it travels through the air. Lapilli tuffs are a very common form of volcanic rock typical of rhyolite, andesite and dacite pyroclastic eruptions, where thick layers of lapilli can be deposited during a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Cone
Volcanic cones are among the simplest volcanic landforms. They are built by ejecta from a volcanic vent, piling up around the vent in the shape of a cone with a central crater. Volcanic cones are of different types, depending upon the nature and size of the fragments ejected during the eruption. Types of volcanic cones include stratocones, spatter cones, tuff cones, and cinder cones. Stratocone Stratocones are large cone-shaped volcanoes made up of lava flows, explosively erupted pyroclastic rocks, and igneous intrusives that are typically centered around a cylindrical vent. Unlike shield volcanoes, they are characterized by a steep profile and periodic, often alternating, explosive eruptions and effusive eruptions. Some have collapsed craters called calderas. The central core of a stratocone is commonly dominated by a central core of intrusive rocks that range from around to over several kilometers in diameter. This central core is surrounded by multiple generations of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Darfur Conflict
The War in Darfur, also nicknamed the Land Cruiser War, is a major armed conflict in the Darfur region of Sudan that began in February 2003 when the Sudan Liberation Movement (SLM) and the Justice and Equality Movement (JEM) rebel groups began fighting against the government of Sudan, which they accused of oppressing Darfur's non-Arab population. The government responded to attacks by carrying out a campaign of ethnic cleansing against Darfur's non-Arabs. This resulted in the death of hundreds of thousands of civilians and the indictment of Sudan's president, Omar al-Bashir, for genocide, war crimes, and crimes against humanity by the International Criminal Court. One side of the conflict is mainly composed of the Sudanese military, police and the Janjaweed, a Sudanese militia group whose members are mostly recruited among Arabized indigenous Africans and a small number of Bedouin of the northern Rizeigat; the majority of other Arab groups in Darfur remained uninvolved. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nyala, Sudan
Nyala ( Daju: "the place of chatting") is the capital of the state of South Darfur in the south-west of Sudan. History Nyala was the capital of the Daju Empire, which was established around Jebel Um-Kurdós. However, many sites of ancient antiquities, pottery, engraved pictures of battles, horses, animals and hunting are still awaiting further scientific archaeological work at Jebel Daju. The most important archaeological sites undiscovered yet are Nari, Kedingnyir, Dobo, Simiat Hills, Jebel Keima, Kalokitting, Jebel Wara, and Jebel Marra itself. When the United Kingdom conquered the present-day Sudan, the British commander-in-chief met Sultan Adam Suleiman in 1932, seeking his advice for his knowledge of the best places in terms of availability of water sources and land topography in order to establish the British Administration Headquarters in Darfur. Sultan Adam Suleiman had chosen Nyala for that purpose. During the ongoing Darfur conflict, thousands of internally displace ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marra Mountains
The Marrah Mountains or Marra Mountains (Fur, Fugo Marra; ar, جبل مرة, Jebel Marra are a range of volcanic peaks in a massif that rises up to . They are the highest mountains in Sudan. Geography The mountains are located in the center of the Darfur region of Sudan on the border of the states of South Darfur and Central Darfur, with a smaller part of the range in the state of North Darfur. The highest point is Deriba Caldera. The upper reaches of the massif is a small area of temperate climate with high rainfall and permanent springs of water amidst the dry savanna and scrub of the Sahel below. Apart from the Aïr Mountains in Niger which are on the border of the Sahara proper, the Marrah Mountains are the only major mountain range in the otherwise flat Sahel, rising up to above the plain, but are relatively unknown owing to lack of development and political conflict in the region. The last eruption occurred around 1500 BC. The centre of activity was Deriba Caldera, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deriba Map
Deriba (Amharic: ደርባ), or Diriba, is a unisex name of Ethiopian origin that may refer to: *Deriba Alemu (born 1983), Ethiopian long-distance runner *Deriba Merga (born 1980), Ethiopian long-distance runner and 2009 Boston Marathon winner *Buze Diriba (born 1994), Ethiopian female long-distance runner and champion at the 2012 World Junior Championships in Athletics The 2012 World Junior Championships in Athletics was an international athletics competition for athletes qualifying as juniors (born 1993 or later) which was held at the Estadi Olímpic Lluís Companys in Barcelona, Catalonia, Spain, on 10–15 ... See also * Deriba Caldera, highest point of the Marrah Mountains {{given name, surname Unisex given names Amharic-language names ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
