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Ice Cauldron
Ice cauldrons are ice formations within glaciers that cover some subglacial volcanoes. They can have circular to oblong forms. Their surface areas reach from some meters (as indentations or holes in the ice) to up to 1 or more kilometers (as bowl shaped depressions). Their existence is connected to ice-volcano interaction in two possible ways: They can be formed in the course of a subglacial eruption or on top of a continuously active subglacial high temperature geothermal area. In both cases, a jökulhlaup may be produced in connection with them. Formation and continued existence of ice cauldrons Ice cauldrons and subglacial eruptions When an eruption takes place under a bigger glacier, e.g. an ice cap, it normally begins with an effusive stage. The heat forms an ice cave and pillow lava is produced. After some time, the eruption has reached a stage where the pressure drops within the ice vault and the eruption style changes to become explosive. Hyaloclastite is produced and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mýrdalsjökull 1 Iceland
Mýrdalsjökull (pronounced , Icelandic language, Icelandic for "(the) Bog, mire dale (origin), dale glacier" or "(the) mire valley glacier") is an ice cap in the south of Iceland. It is to the north of Vík í Mýrdal and to the east of the smaller ice cap Eyjafjallajökull. Between these two glaciers is Fimmvörðuháls pass. Its peak reaches in height and in the year 1980 it covered an area of approximately . The icecap of the glacier covers an active volcano called Katla volcano, Katla. The caldera of the volcano has a diameter of and the volcano erupts usually every 40–80 years. The last eruption took place in 1918. Scientists are actively monitoring the volcano, particularly after the eruption of nearby Eyjafjallajökull began in April 2010. Since the year 930, 16 eruptions have been documented. The Eldgjá, a volcanic eruption fissure about long, which erupted in the year 936, is part of the same volcanic system. Before the Route 1 (Iceland), Hringvegur (the main ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skaftá
The Skaftá () is a river in South Iceland. It is primarily glacial in origin and has had its course modified by volcanic activity; as a result of both, it often floods because of glacial melting. Course The river's primary source is two subglacial "cauldrons" beneath Skaftájökull, part of the Vatnajökull glacier in the interior of Iceland. It also receives spring-fed water from Langisjór, a lake a short distance to the west from which a tributary called the Útfall runs into the Skaftá. Other tributaries include the North and South Ófaerá, the Grjótá, and the Hellisá. West of Skaftárdalur, a farm named for the river valley, the Skaftá runs over a lava field in many channels, which recombine into three for the remainder of its course to the Atlantic: the Eldvatn or Ása-Eldvatn combines with the River Kúðafljót; the Ásakvísl or Árkvísla flows under a sand-covered lava field and has been affected by road construction; the third, easternmost branch, which flows ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earthquake
An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from those that are so weak that they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time period. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume. The word ''tremor'' is also used for Episodic tremor and slip, non-earthquake seismic rumbling. At the Earth's surface, earthquakes manifest themselves by shaking and displacing or disrupting the ground. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Spurr
Mount Spurr ( Dena'ina: ''K'idazq'eni'') is a stratovolcano in the Aleutian Arc of Alaska, named after United States Geological Survey geologist and explorer Josiah Edward Spurr, who led an expedition to the area in 1898. The Alaska Volcano Observatory (AVO) currently rates Mount Spurr as Level of Concern Color Code Green. The mountain is known aboriginally by the Dena'ina Athabascan name ''K'idazq'eni'', literally 'that which is burning inside'. Mount Spurr, the highest volcano of the Aleutian Arc, is a large lava dome constructed at the center of a roughly 5 km-wide horseshoe-shaped caldera that is open to the south. The volcano lies 80.87 miles west of Anchorage and NE of Chakachamna Lake. The caldera was formed by a late-Pleistocene or early Holocene debris avalanche and associated pyroclastic flows that destroyed an ancestral Spurr volcano. The debris avalanche traveled more than 15.5 miles to the SE, and the resulting deposit contains blocks as large as 100m in diame ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Redoubt
Redoubt Volcano, or Mount Redoubt (Denaʼina language, Dena'ina: ''Bentuggezh K’enulgheli''), is an active volcano, active stratovolcano in the largely volcanic Aleutian Range of the U.S. state of Alaska. Located at the head of the Chigmit Mountains subrange in Lake Clark National Park and Preserve, the mountain is just west of Cook Inlet, in the Kenai Peninsula Borough, Alaska, Kenai Peninsula Borough about 110 miles (180 km) southwest of Anchorage, Alaska, Anchorage. At 10,197 feet (3,108 m), in just over 5 miles (8 km) Mount Redoubt attains 9,150 feet (2,700 m) of prominence over its surrounding terrain. It is the highest summit in the Aleutian Range. In 1976, Redoubt Volcano was designated as a National Natural Landmark by the National Park Service. Active for millennia, Mount Redoubt has erupted four times since it was first observed: in 1902, 1966, 1989 and 2009, with two questionable eruptions in 1881 and 1933. The eruption in 1989 spewed volcanic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magmatic System
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural satellites. Besides molten rock, magma may also contain suspended crystals and gas bubbles. Magma is produced by melting of the mantle or the crust in various tectonic settings, which on Earth include subduction zones, continental rift zones, mid-ocean ridges and hotspots. Mantle and crustal melts migrate upwards through the crust where they are thought to be stored in magma chambers or trans-crustal crystal-rich mush zones. During magma's storage in the crust, its composition may be modified by fractional crystallization, contamination with crustal melts, magma mixing, and degassing. Following its ascent through the crust, magma may feed a volcano and be extruded as lava, or it may solidify underground to form an intrusion, such as a di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcano
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and most are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, deep in the Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic plates slide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Settlement Of Iceland
The settlement of Iceland ( is, landnámsöld ) is generally believed to have begun in the second half of the ninth century, when Norse settlers migrated across the North Atlantic. The reasons for the migration are uncertain: later in the Middle Ages Icelanders themselves tended to cite civil strife brought about by the ambitions of the Norwegian king Harald I of Norway, but modern historians focus on deeper factors, such as a shortage of arable land in Scandinavia. Unlike Great Britain and Ireland, Iceland was unsettled land and could be claimed without conflict with existing inhabitants. On the basis of ''Íslendingabók'' by Ari Þorgilsson, and ''Landnámabók'', histories dating from the twelfth and thirteenth centuries and providing a wealth of detail about the settlement, the years 870 and 874 have traditionally been considered the first years of settlement. However, these sources are largely unreliable in the details they provide about the settlement, and recent research ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holocene
The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene together form the Quaternary period. The Holocene has been identified with the current warm period, known as MIS 1. It is considered by some to be an interglacial period within the Pleistocene Epoch, called the Flandrian interglacial.Oxford University Press – Why Geography Matters: More Than Ever (book) – "Holocene Humanity" section https://books.google.com/books?id=7P0_sWIcBNsC The Holocene corresponds with the rapid proliferation, growth and impacts of the human species worldwide, including all of its written history, technological revolutions, development of major civilizations, and overall significant transition towards urban living in the present. The human impact on modern-era Earth and its ecosystems may be considered of global si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
East Volcanic Zone Of Iceland
East or Orient is one of the four cardinal directions or points of the compass. It is the opposite direction from west and is the direction from which the Sun rises on the Earth. Etymology As in other languages, the word is formed from the fact that east is the direction where the Sun rises: ''east'' comes from Middle English ''est'', from Old English ''ēast'', which itself comes from the Proto-Germanic *''aus-to-'' or *''austra-'' "east, toward the sunrise", from Proto-Indo-European *aus- "to shine," or "dawn", cognate with Old High German ''*ōstar'' "to the east", Latin ''aurora'' 'dawn', and Greek ''ēōs'' 'dawn, east'. Examples of the same formation in other languages include Latin oriens 'east, sunrise' from orior 'to rise, to originate', Greek ανατολή anatolé 'east' from ἀνατέλλω 'to rise' and Hebrew מִזְרָח mizraḥ 'east' from זָרַח zaraḥ 'to rise, to shine'. '' Ēostre'', a Germanic goddess of dawn, might have been a personification ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mýrdalsjökull
Mýrdalsjökull (pronounced , Icelandic for "(the) mire dale glacier" or "(the) mire valley glacier") is an ice cap in the south of Iceland. It is to the north of Vík í Mýrdal and to the east of the smaller ice cap Eyjafjallajökull. Between these two glaciers is Fimmvörðuháls pass. Its peak reaches in height and in the year 1980 it covered an area of approximately . The icecap of the glacier covers an active volcano called Katla. The caldera of the volcano has a diameter of and the volcano erupts usually every 40–80 years. The last eruption took place in 1918. Scientists are actively monitoring the volcano, particularly after the eruption of nearby Eyjafjallajökull began in April 2010. Since the year 930, 16 eruptions have been documented. The Eldgjá, a volcanic eruption fissure about long, which erupted in the year 936, is part of the same volcanic system. Before the Hringvegur (the main ring road round the island) was built, people feared traversing the pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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