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Hekla (A
Hekla (), or Hecla, is a stratovolcano in the south of Iceland with a height of . Hekla is one of Iceland's most active volcanoes; over 20 eruptions have occurred in and around the volcano since 874. During the Middle Ages, the Icelandic Norse called the volcano the "Gateway to Hell". Hekla is part of a volcanic ridge, long. The most active part of this ridge, a Fissure vent, fissure about long named , is considered to be within Hekla proper. Hekla looks rather like an overturned boat, with its keel being a series of craters, two of which are generally the most active. The volcano's frequent large eruptions have covered much of Iceland with tephra, and these layers can be used to date eruptions of Iceland's other volcanoes. Approximately 10% of the tephra created in Iceland in the last thousand years has come from Hekla, amounting to 5 km3. Cumulatively, the volcano has produced one of the largest volumes of lava of any in the world in the last millennium, around 8 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Þjórsá
Þjórsá () is Iceland's longest river at 230 kilometers (about 143 miles). It is in the south of the island. Þjórsá is a glacier river and has its source on the glacier Hofsjökull. It flows out through narrow gorges in the highlands of Iceland. Further downstream, another river, the Tungnaá, flows into it (see also Háifoss), before it enters the lowlands. There it passes the valley of Þjórsárdalur (Thjorsardalur) where the historical farm of Stöng is located. In the lowlands it flows along the eastern border of the Great Þjórsá Lava. In the middle of the now rather wide river, there is a big island called ''Árnes'', where there used to be a '' Þing''. The administrative unit of Árnessýsla was named after it. The ''hringvegur'' (Road No.1) traverses the river via a bridge between Selfoss and Hella. Some kilometers to the southwest the river flows into the Atlantic Ocean. 'Á' signifies river while 'þjór' means bull and is cognate to Danish - tyr, Swedish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sicily
(man) it, Siciliana (woman) , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = Ethnicity , demographics1_footnotes = , demographics1_title1 = Sicilian , demographics1_info1 = 98% , demographics1_title2 = , demographics1_info2 = , demographics1_title3 = , demographics1_info3 = , timezone1 = CET , utc_offset1 = +1 , timezone1_DST = CEST , utc_offset1_DST = +2 , postal_code_type = , postal_code = , area_code_type = ISO 3166 code , area_code = IT-82 , blank_name_sec1 = GDP (nominal) , blank_info_sec1 = €89.2 billion (2018) , blank1_name_sec1 = GDP per capita , blank1_info_sec1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorine
Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists at standard conditions as a highly toxic, pale yellow diatomic gas. As the most electronegative reactive element, it is extremely reactive, as it reacts with all other elements except for the light inert gases. Among the elements, fluorine ranks 24th in universal abundance and 13th in terrestrial abundance. Fluorite, the primary mineral source of fluorine which gave the element its name, was first described in 1529; as it was added to metal ores to lower their melting points for smelting, the Latin verb meaning 'flow' gave the mineral its name. Proposed as an element in 1810, fluorine proved difficult and dangerous to separate from its compounds, and several early experimenters died or sustained injuries from their attempts. Only in 1886 did French chemist Henri Moissan isolate elemental fluorine using low-temperature electrolysis, a process still employed for modern pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magma Chamber
A magma chamber is a large pool of liquid rock beneath the surface of the Earth. The molten rock, or magma, in such a chamber is less dense than the surrounding country rock, which produces buoyant forces on the magma that tend to drive it upwards. If the magma finds a path to the surface, then the result will be a volcanic eruption; consequently, many volcanoes are situated over magma chambers. These chambers are hard to detect deep within the Earth, and therefore most of those known are close to the surface, commonly between 1 km and 10 km down. Dynamics of magma chambers Magma rises through cracks from beneath and across the crust because it is less dense than the surrounding rock. When the magma cannot find a path upwards it pools into a magma chamber. These chambers are commonly built up over time, by successive horizontal or vertical magma injections. Influx of new magma causes reaction of pre-existing crystals and the pressure in the chamber to increase. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Revista De La Asociación Geológica Argentina
The ''Revista de la Asociación Geológica Argentina'' is an open access peer-reviewed scientific journal published by the Asociación Geológica Argentina. The journal is released under a CC-BY-NC 2.5 license. - official website See also * ''Andean Geology
''Andean Geology'' (formerly ''Revista Geológica de Chile'') is a peer-reviewed scientific journal published three times per year by the National Geology and Mining Service, Chile's geology and mining agency. The journal covers the field of geol ... ''
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Chile
Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east and the Pacific Ocean to the west. Chile covers an area of , with a population of 17.5 million as of 2017. It shares land borders with Peru to the north, Bolivia to the north-east, Argentina to the east, and the Drake Passage in the far south. Chile also controls the Pacific islands of Juan Fernández, Isla Salas y Gómez, Desventuradas, and Easter Island in Oceania. It also claims about of Antarctica under the Chilean Antarctic Territory. The country's capital and largest city is Santiago, and its national language is Spanish. Spain conquered and colonized the region in the mid-16th century, replacing Inca rule, but failing to conquer the independent Mapuche who inhabited what is now south-central Chile. In 1818, after declaring in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Callaqui
Callaqui is a stratovolcano located in the Bío Bío Region of Chile. It is a large ice-capped, basaltic andesite volcano which is elongated in the northeast-southwest direction, due to its construction along an long fissure. Numerous cinder cones and lava flows have erupted from vents along this linear fissure. Most of the activity at Callaqui has been fumarolic. Minor eruptions were reported 1751, 1864, and 1937, and the latest eruption was a small phreatic eruption in 1980. Together with Hekla in Iceland, Callaqui is one of the few volcanoes with have a morphology between a crater row and stratovolcano (built from mixed lava and tephra eruptions). The volcano is the centerpiece of Ralco National Reserve. See also * List of volcanoes in Chile The Smithsonian Institution's Global Volcanism Program lists 105 volcanoes in Chile that have been active during the Holocene. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transform Fault
A transform fault or transform boundary, is a fault along a plate boundary where the motion is predominantly horizontal. It ends abruptly where it connects to another plate boundary, either another transform, a spreading ridge, or a subduction zone. A transform fault is a special case of a ''strike-slip fault'' that also forms a plate boundary. Most such faults are found in oceanic crust, where they accommodate the lateral offset between segments of divergent boundaries, forming a zigzag pattern. This is a result of oblique seafloor spreading where the direction of motion is not perpendicular to the trend of the overall divergent boundary. A smaller number of such faults are found on land, although these are generally better-known, such as the San Andreas Fault and North Anatolian Fault. Nomenclature Transform boundaries are also known as conservative plate boundaries because they involve no addition or loss of lithosphere at the Earth's surface. Background Geophysicist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fissure Vent
A fissure vent, also known as a volcanic fissure, eruption fissure or simply a fissure, is a linear volcanic vent through which lava erupts, usually without any explosive eruption, explosive activity. The vent is often a few metres wide and may be many kilometres long. Fissure vents can cause large flood basalts which run first in lava channels and later in lava tubes. After some time, the eruption tends to become focused at one or more spatter cones. Small fissure vents may not be easily discernible from the air, but the crater rows (see Laki) or the canyons (see Eldgjá) built up by some of them are. The Dike_(geology)#Magmatic_dikes, dikes that feed fissures reach the surface from depths of a few kilometers and connect them to deeper magma chamber, magma reservoirs, often under volcanic centers. Fissures are usually found in or along rifts and rift zones, such as Iceland and the East African Rift. Fissure vents are often part of the structure of shield volcanoes. Icelan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic System Of Iceland-Map-en
A volcano is a rupture in the Crust (geology), crust of a Planet#Planetary-mass objects, planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and volcanic gas, gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where list of tectonic plates, tectonic plates are divergent boundary, diverging or convergent boundary, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Easter
Easter,Traditional names for the feast in English are "Easter Day", as in the '' Book of Common Prayer''; "Easter Sunday", used by James Ussher''The Whole Works of the Most Rev. James Ussher, Volume 4'') and Samuel Pepys''The Diary of Samuel Pepys, Volume 2'') as well as the single word "Easter" in books printed i157515841586 also called Pascha (Aramaic, Greek, Latin) or Resurrection Sunday, is a Christian festival and cultural holiday commemorating the resurrection of Jesus from the dead, described in the New Testament as having occurred on the third day of his burial following his crucifixion by the Romans at Calvary . It is the culmination of the Passion of Jesus Christ, preceded by Lent (or Great Lent), a 40-day period of fasting, prayer, and penance. Easter-observing Christians commonly refer to the week before Easter as Holy Week, which in Western Christianity begins on Palm Sunday (marking the entrance of Jesus in Jerusalem), includes Spy Wednesday (on whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Witch
Witchcraft traditionally means the use of Magic (supernatural), magic or supernatural powers to harm others. A practitioner is a witch. In Middle Ages, medieval and early modern Europe, where the term originated, accused witches were usually women who were believed to have used Black magic, malevolent magic against their own community, and often to have communed with evil beings. It was thought witchcraft could be thwarted by Apotropaic magic, protective magic or counter-magic, which could be provided by cunning folk or folk healers. Suspected witches were also intimidated, banished, attacked or killed. Often they would be formally prosecuted and punished, if found guilty or simply believed to be guilty. European witch-hunts and witch trials in the early modern period led to tens of thousands of executions. In some regions, many of those accused of witchcraft were folk healers or midwife, midwives. European belief in witchcraft gradually dwindled during and after the Age of Enl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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