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Sector Collapse
A sector collapse is the collapse of a portion of a volcano due to a phreatic eruption, an earthquake, or the intervention of new magma. Occurring on many volcanoes, sector collapses are generally one of the most hazardous volcanic events, and will often create lateral blasts. Examples A sector collapse was documented during the 1980 eruption of Mount St. Helens. It occurred due to an earthquake that was a result of the eruption. In Italy, the Sciara del Fuoco is a scar left by a sector collapse that happened over 5000 years ago. The volcano involved was the Stromboli volcano. A sector collapse occurred during an eruption of a volcano in Nicaragua Nicaragua (; ), officially the Republic of Nicaragua (), is the largest country in Central America, bordered by Honduras to the north, the Caribbean to the east, Costa Rica to the south, and the Pacific Ocean to the west. Managua is the cou .... References Volcanoes Geology terminology {{volcanology-stub ... [...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] |
Phreatic Eruption
A phreatic eruption, also called a phreatic explosion, ultravulcanian eruption or steam-blast eruption, occurs when magma heats ground water or surface water. The extreme temperature of the magma (anywhere from ) causes near-instantaneous evaporation of water to steam, resulting in an explosion of steam, water, ash, rock, and volcanic bombs. At Mount St. Helens in Washington state, hundreds of steam explosions preceded the 1980 Plinian eruption of the volcano. A less intense geothermal event may result in a mud volcano. Phreatic eruptions typically include steam and rock fragments; the inclusion of liquid lava is unusual. The temperature of the fragments can range from cold to incandescent. If molten magma is included, volcanologists classify the event as a phreatomagmatic eruption. These eruptions occasionally create broad, low-relief craters called '' maars''. Phreatic explosions can be accompanied by carbon dioxide or hydrogen sulfide gas-emissions. Carbon dioxide c ... [...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] |
Magma
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateral Blast
A lateral eruption or lateral blast is a volcanic eruption which is directed laterally from a volcano rather than upwards from the summit. Lateral eruptions are caused by the outward expansion of flanks due to rising magma. Breaking occurs at the flanks of volcanoes making it easier for magma to flow outward. As magma is pushed upward towards the volcano it diverges towards the flanks before it has a chance to erupt from the crater. When the expanding flank finally gives it releases a flow of magma. More explosive lateral eruptions are referred to as lateral blasts. Some of the most notable examples of a lateral eruption include Mount St. Helens, Mount Pelée, and Mount Etna. Creation of a lateral eruption Most eruptions are caused by the immediate decompression of a magma chamber near the flanks of the volcano. During an eruption, the rapid decompression of magma may cause subsidence of the mountain, and if a flank collapses, a lateral eruption occurs. The directed nature of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1980 Eruption Of Mount St
__NOTOC__ Year 198 (CXCVIII) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Sergius and Gallus (or, less frequently, year 951 ''Ab urbe condita''). The denomination 198 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire *January 28 **Publius Septimius Geta, son of Septimius Severus, receives the title of Caesar. **Caracalla, son of Septimius Severus, is given the title of Augustus. China *Winter – Battle of Xiapi: The allied armies led by Cao Cao and Liu Bei defeat Lü Bu; afterward Cao Cao has him executed. By topic Religion * Marcus I succeeds Olympianus as Patriarch of Constantinople (until 211). Births * Lu Kai (or Jingfeng), Chinese official and general (d. 269) * Quan Cong, Chinese general and advisor (d. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Italy
Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical region. Italy is also considered part of Western Europe, and shares land borders with France, Switzerland, Austria, Slovenia and the enclaved microstates of Vatican City and San Marino. It has a territorial exclave in Switzerland, Campione. Italy covers an area of , with a population of over 60 million. It is the third-most populous member state of the European Union, the sixth-most populous country in Europe, and the tenth-largest country in the continent by land area. Italy's capital and largest city is Rome. Italy was the native place of many civilizations such as the Italic peoples and the Etruscans, while due to its central geographic location in Southern Europe and the Mediterranean, the country has also historically been home ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sciara Del Fuoco
Sciara del Fuoco is a Scree, talus scree or depression located on Stromboli, Stromboli Island in Italy. It runs along the island's northern flank and is bounded by two ridges. It now serves as a major tourist attraction on the island. Formation Sciara del Fuoco was formed as a result of a sector collapse around 5,000 years ago. Due to this, it is sometimes referred to as a scar. It was formed by lava, lapilli and Incandescence, incandescent waste. References Volcanoes of Italy Stromboli {{Europe-geologic-formation-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stromboli
Stromboli ( , ; scn, Struògnuli ) is an island in the Tyrrhenian Sea, off the north coast of Sicily, containing Mount Stromboli, one of the four active volcanoes in Italy. It is one of the eight Aeolian Islands, a volcanic arc north of Sicily. Strabo writes that people believed that this is where Aeolus lived. The island, with an area of , represents the upper third of the volcano. Its population was about 500 . The volcano has erupted many times and is constantly active with minor eruptions, often visible from many points on the island and from the surrounding sea, giving rise to the island's nickname "Lighthouse of the Mediterranean". Etymology Its name is derived from the Ancient Greek name , (Στρογγύλη) which was derived from (, "round"), after the volcano's round, conical appearance when seen from a distance. Height and shape Stromboli is an island in the Tyrrhenian Sea, off the north coast of Sicily, containing Mount Stromboli, one of the three active vol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicaragua
Nicaragua (; ), officially the Republic of Nicaragua (), is the largest country in Central America, bordered by Honduras to the north, the Caribbean to the east, Costa Rica to the south, and the Pacific Ocean to the west. Managua is the country's capital and largest city. , it was estimated to be the second largest city in Central America. Nicaragua's multiethnic population of six million includes people of mestizo, indigenous, European and African heritage. The main language is Spanish. Indigenous tribes on the Mosquito Coast speak their own languages and English. Originally inhabited by various indigenous cultures since ancient times, the region was conquered by the Spanish Empire in the 16th century. Nicaragua gained independence from Spain in 1821. The Mosquito Coast followed a different historical path, being colonized by the English in the 17th century and later coming under British rule. It became an autonomous territory of Nicaragua in 1860 and its northernmost part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanoes
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 pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
