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Katla (volcano)
Katla () is an active subglacial volcano in Farthings of Iceland, southern Iceland. This volcano has been very active historically with at least twenty documented major eruptions since 2920 BC. In its recent history though, Katla has been less active as the last major eruption occurred in 1918. These eruptions have had a Volcanic Explosivity Index (VEI) of between 4 and 5 on a scale of 0 to 8. In comparison, the Eyjafjallajökull 2010 eruption had a VEI of 4. Larger VEI-5 eruptions are comparable to Mount St. Helens 1980 eruption of Mount St. Helens, 1980 eruption. These eruptions have produced very large glacial outburst floods. Several smaller (minor) events measuring Volcanic explosivity index, VEI-1 and below have occurred since. Katla is one of the largest volcanic sources of Carbon dioxide, carbon dioxide (CO2) on Earth, accounting for up to 4% of total global volcanic carbon dioxide emissions. Geography and physical appearances Katla is one of the largest volcanoes in I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Eruption
A volcanic eruption occurs when material is expelled from a volcanic vent or fissure. Several types of volcanic eruptions have been distinguished by volcanologists. These are often named after famous volcanoes where that type of behavior has been observed. Some volcanoes may exhibit only one characteristic type of eruption during a period of activity, while others may display an entire sequence of types all in one eruptive series. There are three main types of volcanic eruptions. Magmatic eruptions involve the decompression of gas within magma that propels it forward. Phreatic eruptions are driven by the superheating of steam due to the close proximity of magma. This type exhibits no magmatic release, instead causing the granulation of existing rock. Phreatomagmatic eruptions are driven by the direct interaction of magma and water, as opposed to phreatic eruptions, where no fresh magma reaches the surface. Within these broad eruptive types are several subtypes. The we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caldera
A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcanic eruption. An eruption that ejects large volumes of magma over a short period of time can cause significant detriment to the structural integrity of such a chamber, greatly diminishing its capacity to support its own roof and any substrate or rock resting above. The ground surface then collapses into the emptied or partially emptied magma chamber, leaving a large depression at the surface (from one to dozens of kilometers in diameter). Although sometimes described as a Volcanic crater, crater, the feature is actually a type of sinkhole, as it is formed through subsidence and collapse rather than an explosion or impact. Compared to the thousands of volcanic eruptions that occur over the course of a century, the formation of a caldera is a rare event, occurring only a few times within a given window of 100 years. Only eight caldera-forming collapses are known to have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mýrdalssandur
Mýrdalssandur () is an outwash plain on the south coast of Iceland. Location and description The outwash plain is located between the rivers of Kúðafljót in the east and Múlakvísl in the west. Both rivers carry water from the Mýrdalsjökull glacier to the sea. Mýrdalssandur has a -long coast line, including Kötlutangi , the southernmost point of the island of Iceland. The Ring Road crosses this flat surface on . Development The outwash plain was built by the numerous jökulhlaups of the Mýrdalsjökull. The last large jökulhlaup was due to an explosive eruption of the Katla volcano under the glacier in 1918, and the water volume at the peak of the jökulhlaup was estimated to be around 200,000 - 300,000 m³/s. History of settlements South of the road rises Hjörleifshöfði to a height of . The mountain is named after Hjörleifr Hróðmarsson. He was the first settler to come to Iceland with Ingólfr Arnarson. In the Middle Ages there was a fishing lake called ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jökulhlaup
A jökulhlaup ( ) (literally "glacial run") is a type of glacial outburst flood. It is an Icelandic term that has been adopted in glaciological terminology in many languages. It originally referred to the well-known subglacial outburst floods from Vatnajökull, Iceland, which are triggered by geothermal heating and occasionally by a volcanic subglacial eruption, but it is now used to describe any large and abrupt release of water from a subglacial or proglacial lake/reservoir. Since jökulhlaups emerge from hydrostatically sealed lakes with floating levels far above the threshold, their peak discharge can be much larger than that of a marginal or extra-marginal lake burst. The hydrograph of a jökulhlaup from Vatnajökull typically either climbs over a period of weeks with the largest flow near the end, or it climbs much faster during the course of some hours. These patterns are suggested to reflect channel melting, and sheet flow under the front, respectively. Similar p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lahar
A lahar (, from ) is a violent type of mudflow or debris flow composed of a slurry of Pyroclastic rock, pyroclastic material, rocky debris and water. The material flows down from a volcano, typically along a valley, river valley. Lahars are often extremely destructive and deadly; they can flow tens of metres per second, they have been known to be up to deep, and large flows tend to destroy any structures in their path. Notable lahars include those at Mount Pinatubo in the Philippines and Nevado del Ruiz in Colombia, the latter of which killed more than 20,000 people in the Armero tragedy. Etymology The word ''lahar'' is of Javanese language, Javanese origin. Berend George Escher introduced it as a geological term in 1922. Description The word ''lahar'' is a general term for a flowing mixture of water and pyroclastic debris. It does not refer to a particular rheology or sediment concentration. Lahars can occur as normal stream flows (sediment concentration of less than 30%), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1918 Eruption Of Katla
Between October and November 1918 a series of jökulhlaups, a type of glacial outburst flood, following an eruption of Katla in Iceland caused significant property damage and disruption in Iceland with local depopulation. Background Katla is an active volcano in the south-east of Iceland. It is covered by the Mýrdalsjökull ice cap. Over 300 basaltic eruptions may have occurred in the Holocene. The 1918 eruption was amongst the largest 20th century eruptions in Iceland. Geology This was a typical hydromagmatic basaltic eruption below the Mýrdalsjökull ice cap, although explosive silicic eruptions are known from the volcano. The eruption produced a bulk volume of tephra of up to and eruption cloud height of at least . The total dry rock equivalent erupted was up to . Events Seismic signs of unrest are reported to have started at about 11:30am local time on 12 October 1918 with ripples observed in a bucket of water and at about 1pm an earthquake was felt at Vík í M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Location Of Katlas Caldera
In geography, location or place is used to denote a region (point, line, or area) on Earth's surface. The term ''location'' generally implies a higher degree of certainty than ''place'', the latter often indicating an entity with an ambiguous boundary, relying more on human or social attributes of place identity and sense of place than on geometry. A populated place is called a '' settlement''. Types Locality A locality, settlement, or populated place is likely to have a well-defined name but a boundary that is not well defined, but rather varies by context. London, for instance, has a legal boundary, but this is unlikely to completely match with general usage. An area within a town, such as Covent Garden in London, also almost always has some ambiguity as to its extent. In geography, location is considered to be more precise than "place". Relative location A relative location, or situation, is described as a displacement from another site. gta6 Absolute location An absolute l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kettle
A kettle, sometimes called a tea kettle or teakettle, is a device specialized for boiling water, commonly with a ''lid'', ''spout'', and ''handle''. There are two main types: the ''stovetop kettle'', which uses heat from a cooktop, hob, and the ''electric kettle'', which is a small appliance, small kitchen appliance with an internal heating element. Etymology The word ''kettle'' originates from Old Norse ''ketill'', "cauldron". The Old English spelling was ''cetel'' with initial ''che-'' [tʃ] like 'cherry', Middle English (and dialectal) was ''chetel'', both come (together with German ''Kessel'' "cauldron") ultimately from Germanic ''*katilaz'', that was borrowed from Latin ''catillus'', diminutive form of ''catinus'' "deep vessel for serving or cooking food", which in various contexts is translated as "bowl", "deep dish", or "funnel". Stovetop kettles A modern stovetop kettle is a metal vessel with a flat bottom used to heat water on a stovetop, stovetop or hob. They usua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yangtze River
The Yangtze or Yangzi ( or ) is the longest river in Eurasia and the third-longest in the world. It rises at Jari Hill in the Tanggula Mountains of the Tibetan Plateau and flows including Dam Qu River the longest source of the Yangtze, in a generally easterly direction to the East China Sea. It is the fifth-largest primary river by discharge volume in the world. Its drainage basin comprises one-fifth of the land area of China, and is home to nearly one-third of the country's population. The Yangtze has played a major role in the history, culture, and economy of China. For thousands of years, the river has been used for water, irrigation, sanitation, transportation, industry, boundary-marking, and war. The Yangtze Delta generates as much as 20% of China's GDP, and the Three Gorges Dam on the Yangtze is the largest hydro-electric power station in the world. In mid-2014, the Chinese government announced it was building a multi-tier transport network, comprising railways, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nile
The Nile (also known as the Nile River or River Nile) is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa. It has historically been considered the List of river systems by length, longest river in the world, though this has been contested by research suggesting that the Amazon River is slightly longer.Amazon Longer Than Nile River, Scientists Say Of the world's major rivers, the Nile has one of the lowest average annual flow rates. About long, its drainage basin covers eleven countries: the Democratic Republic of the Congo, Tanzania, Burundi, Rwanda, Uganda, Kenya, Ethiopia, Eritrea, South Sudan, Sudan, and Egypt. In pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mississippi River
The Mississippi River is the main stem, primary river of the largest drainage basin in the United States. It is the second-longest river in the United States, behind only the Missouri River, Missouri. From its traditional source of Lake Itasca in northern Minnesota, it flows generally south for to the Mississippi River Delta in the Gulf of Mexico. With its many tributaries, the Mississippi's Drainage basin, watershed drains all or parts of 32 U.S. states and two Canadian provinces between the Rocky Mountains, Rocky and Appalachian Mountains, Appalachian mountains. The river either borders or passes through the states of Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana. The main stem is entirely within the United States; the total drainage basin is , of which only about one percent is in Canada. The Mississippi ranks as the world's List of rivers by discharge, tenth-largest river by discharge flow, and the largest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
