[141] The Plinian deposit has a colour ranging from white to creamy. The largest historical eruption of Lascar took place in 1993, producing pyroclastic flows to 8.5 km NW of the summit. [157] The 1933 eruption was seen as far away as Chuquicamata. This information was summarized from the GVP/USGS Weekly Volcanic Activity Report. [86], The Soncor deposit was subsequently affected by glaciation[67] and the stage I edifice by a debris avalanche,[39] which was radiocarbon dated at 22,310 +2,700/2000 years ago in the Quebrada de Chaile. [129] Lava bombs with diameters of up to 1.5 metres (4ft 11in) were hurled as far as 4 kilometres (2.5mi) from the crater, presumably as a consequence of the lava dome exploding. [189] Pumice mostly accumulated on the surface of the flows, and individual stones are up to 30 centimetres (12in) wide. [47] These valleys were probably formed by erosion during glacial periods. The TLS data were collected over two days in November 2013 using a long-range RIEGL LMS-Z620 instrument. [111] There is no clear association between periods of degassing and eruptions. [195], These flows took a long time to cool down; in the Quebrada Tumbres, they had not cooled down completely by December 1993. [144], The magma erupted was generated in a magma chamber starting from andesite, which underwent complex petrogenetic processes. In the deep valleys, groundwater and streams support more plants. [92] The conditions at the magma chamber may be comparable to these under which epithermal mineral deposits form. [143] The deposits are formed by a Plinian fallout deposit and an ignimbrite rich in lithics. [6] The present-day snowline in the region lies at an altitude of 6,050 metres (19,850ft), higher than the summit of Lascar. [10] Unlike the neighbouring volcanoes Acamarachi, Licancabur and Quimal, there is no evidence of archeological sites on Lascar,[11] possibly because of the volcanic activity. [7] As of 2017[update], stockbreeding and farming were the principal economic activities in Talabre. The lava dome had disappeared, but in early 1992, another lava dome formed, eventually reaching a size of 180190 metres (590620ft) width and 40 metres (130ft) height, and was accompanied by explosions. [86], The magma chamber of Lascar appears to lie at depths of 1017 kilometres (6.210.6mi),[87] although the lack of deformation of the edifice during the 1993 eruption indicates that it may be deeper, over 2530 kilometres (1619mi) or even over 40 kilometres (25mi) deep. Lascar is the most active volcano in the central Andes. Created by. Test. [99], There are high-temperature fumaroles (temperatures equal to or exceeding 150C (302F)) and low-temperature fumaroles (temperatures of less than 82C (180F)), with noticeable chemical differences between the two; the latter tend to emit far more water than carbon dioxide. A volcano in the Andes in Chile's north rumbled to life on Saturday, triggering minor earth tremors and sending a plume of smoke and ash thousands of metres into the sky.. Chile's National Geology and Mining Service reported that the Lascar volcano stirred at 12.36pm. Because the former are. [59], Layers of lava and pyroclastics are discernible in the craters. Saumya joshi. [214] During April 1993, a new lava dome formed in the crater, reaching a diameter of 380 metres (1,250ft). The San Andreas Fault Zone is not the only active transform plate boundary with U. S. National Park Service sites. [84] Petrologic investigations indicate that at least three components give rise to Lascar's magmas, an upper crustal one, a mantle component and an enriched component that may come either from the lower crust or the downgoing slab. [53], Lascar has erupted about thirty times since the 19th century. [229] This eruption may have been triggered by a precipitation event which added water to the volcan's hydrothermal system. [213] The 1993 eruption was followed by a significant increase in the fluorine content of plants covered by the ash. [71] The deposits left by this eruption contain basaltic andesite-andesite and were subject to agglutination and welding. [245] High nickel concentrations in crops from Talabre appear to be caused by volcanic activity as well. Data is available for free at doi.org/10.5880/GFZ.2.1.2016.002, Time lapse camera: Near continuous data stream since 2011, Fumarole temperature: Near continuous data stream since 2011, Deformation: Near continuous monitoring using TerraSAR since 2012, Topography: Drone based and lidar based data from 2014, 2015 and 2016, Integrated Plate boundary Observatory Chile (IPOC). [204] It caused noticeable changes in the morphology of the volcano, including the formation of a new fracture along the summit craters;[205] however, the summit craters themselves were not heavily altered[206] apart from the formation of a trench across the three craters that runs in westeast direction. The flow deposit was later modified by glacial activity. [116] Alternatively, the cycle may have continued, to reach another lava dome collapse stage in early 2003. [19] It is possible that when these ridges are subducted, the buoyancy they carry disrupts the subduction process and reduces the supply of water, which is important for the formation of melts. Every donation will be highly appreciated. It is the most active volcano in the region, with records of eruptions going back to 1848. It probably started shrinking in April 1992, although the shrinkage was directly visible only in November. [242] In 1982,[243] the town of Talabre was moved for safety reasons[52] stemming from flooding and volcanic activity,[243] and ballistic blocks ejected by the volcano are a threat to mountaineers and scientists working on Lascar. [134] These deposits have volumes of 0.1 cubic kilometres (0.024cumi) and probably formed when an explosive eruption took place in a lava lake. [3] Other names for the volcano are Hlscar,[4] Hlascar, Ilascar, Kar Las, Laskar, Toconado and Toconao. The Cascade volcanoes in the northwestern United States and the volcanoes in Mexico and Central America are related to the subduction under the North American Plate of the small Juan de Fuca and Cocos plates, which are on the east side of the Pacific Plate. [45] Noticeable erosion occurred in the areas over which pyroclastic flows had passed, forming abrasion surfaces and removing loose detritus from the ground. To the left, in the background, the. Add an answer. It is an andesitic to dacitic stratovolcano with six overlapping craters, trending roughly northeast, with the active, fuming crater located near the center. [51] This dacitic lava was erupted on Lascar at high altitude and has a blocky surface. Carbon in the gases may come from skarn assimilation. [53] Activity has alternated between the eastern and western part of the volcano during its history. [54] The Soncor flow is found primarily on the western side of Lascar, with part of it also southeast of Lascar. [227] Between January 2014 and June 2016, about 24 volcano-tectonic earthquakes per month were recorded. The name originates from the Atacameo word lskar or lassi (English: tongue), thought to refer to the shape of the volcano. The Lascar Volcano is an active andesitic to dacitic stratovolcano that consists of an elongate series of six overlapping craters, trending roughly northeast, with the active, fuming crater located near the center of this cluster. Volcanoes at convergent plate boundaries are found all along the Pacific Ocean basin, primarily at the edges of the Pacific, Cocos, and Nazca plates. [123] Electrical conductivity data suggest that a hydrothermal system exists beneath Lascar,[124] but the existence of such a system has been questioned. Hornfels, skarn, and rocks that are part of Lascar's lava dome ridge are the source of these xenoliths. [78] SiO2 concentrations range from 55.5 to 67.8% by weight, and the rocks have medium to large concentrations of potassium. [175] The total mass flux of the eruption was about 10,000,000100,000,000 kilograms per second (860,000,0008.64109t/d), comparable to the 1982 eruption of El Chichon. [228] The last eruption, on 30 October 2015, created a 2,500-metre-high (8,200ft) column of ash that prompted a raise in the local volcano alert level. Volcanic activity is characterized by constant release of volcanic gas and occasional vulcanian eruptions. Data available through GEOFON. The volcano experienced at least three major eruptions throughout its history: One is the Soncor eruption about 26,450 500 years ago, another in 7,250 BCE and the third in 1993. [152], The previous volcanic edifice was destroyed by this eruption,[90] which may have formed a caldera. [129] In March 1990, the lava dome had a temperature of 100200C (212392F), with some parts exceeding 900C (1,650F). It is about 800 m in diameter and 300 m deep. The equilibrium line at Lascar was at an altitude of 4,7004,800 metres (15,40015,700ft) during the last glacial maximum. lascar volcano volcano type stratco or composite eruption history volcano location type of lava flow eruption type last eruption:October 31 Chile andesite plate boundaries and where the volcano is formed or located how lascar was formed plate boundaries: convergent subduction. [140] The Soncor magmas were associated with a volatile phase that underwent extensive interaction with the future eruption products. [252] Other reports claim that flamingos remained; other animals like donkeys and llamas were seen around the volcano one day after its eruption.[209]. Minerals encountered in xenoliths include andradite, anhydrite, anorthite, apatite, biotite, calcite, diopside, fassaite, garnet, gypsum, ilmenite, magnetite, monazite, orthopyroxene, perovskite, plagioclase, prehnite, quartz, sphene, thorite, wilkeite, wollastonite and zircon. [44] These lava domes are about 5 million years old,[51] and are composed of dacite and smaller amounts of pyroxene andesite,[49] along with rhyolite and visible minerals including biotite and hornblende. [39] They reach thicknesses of 5 metres (16ft) in the upper unit[133] and 30 metres (98ft) in the lower one. The chamber may be surrounded by skarnic alteration. Lithic rocks derived both from the pre-Soncor volcano and the basement are also represented. [147] Magma temperatures have been estimated at 9001,000C (1,6501,830F). [222] The 18 April eruption was seen from the El Abra copper mine 220 kilometres (140mi) away and resulted in ash fall north-northeast from the volcano. [36] Traces of glaciation also exist at Cerros de Saltar. [60] These craters are not collapsed calderas,[57] and there is no evidence of the deposits a large explosion would produce. However, an eruption of the Cerro Corona lava dome occurred during this period,[60] and activity of stage III did not commence earlier than 22,300 years ago. [145] The ignimbrite features three facies, one rich in breccia, another rich in pumice, and a normal ignimbrite. [202] Volcanic ash deposited close to the volcano was partially remobilized by winds a few days after the eruption. [128] The towns of Tumbres and Talabre may be affected by pyroclastic flows, and ash falls can occur east of the volcano. [67], A major Plinian eruption occurred 26,450 500 years ago,[137] releasing 1015 cubic kilometres (2.43.6cumi) of ejecta, both volcanic ash and pyroclastic flows. [77], The rocks of Lascar belong to the calc-alkaline series. Contact of lead scientist: T.R. The western edifice generated a complex of lava domes (stage II),[53] which was probably surrounded by a horseshoe-shaped crater open to the west. [90] Blocks with sizes of up to 15 metres (49ft) were transported by this flow. The Chaile flows are actually formed by two separate units and are found on the southwest flanks of the volcano, up to a distance of 6 kilometres (3.7mi). [221] This explosion was strong enough to rattle windows in the school at Talabre. The deposits left contain both andesite and dacite,[53] with phenocrysts consisting of apatite, augite, biotite, iron-titanium oxides, orthopyroxene and plagioclase in a rhyolite matrix. These rocks have a composition mainly characterized as "two-pyroxene",[a] but the old Piedras Grandes and Soncor rocks contain hornblende. Data allows to study structural and geomorphological features at the nested craters of Lscar Volcano, Chile. [9], Lascar is located atop of a ridge formed by the 5,293-metre-high (17,365ft) Cerro Corona and 5,192-metre-high (17,034ft) Cerro de Saltar lava domes, south and north of Lascar, respectively. It is the most active volcano in the region, with records of eruptions going back to 1848. SERNAGEOMIN reported that seismic signals characterized as moderate were recorded on 19 December and located near Lscar's main crater at shallow depths. It has a volume of 56 cubic kilometres (1.21.4cumi). [58] The craters show evidence that activity has migrated westward. [165] The eruption itself lasted only about five minutes and consisted of two pulses. [78] This occurs because as the magma loses its gas content, the number of pores in it, and thus its permeability to gas, decreases. [238] It publishes a volcano alert level for Lascar and has created a volcano hazard map for the volcano. [9], Lascar, like El Tatio, is a destination for volcano tourism. [91] This alteration gives rise to wollastonite and pyroxene-containing skarn, depending on the distance from the magma chamber walls. Subsequently, a number of fumaroles were active around the crater. [153] The Capricorn Lava overlies the Soncor deposits. [23], About 122 volcanoes with Holocene eruptions exist in the Andean Volcanic Belt, including Ojos del Salado which with a height of 6,887 metres (22,595ft) is the highest volcano in the world. Science of Geology and Scientific Method 1. [129] The Observatorio Volcanolgico de los Andes del Sur in Temuco also employs webcams to watch Lascar. Estimated temperatures decreased from 800900C (1,4701,650F) at the vent to 580600C (1,0761,112F) farther down the flows. [104] Overall sulfur output ranges between 200 and 2,300 tonnes per day (2.3 and 26.6kg/s). [35], A 200-metre-wide (660ft) and 50-metre-high (160ft) lava dome formed in early 1989. [54] Exposures of the basement are often delimited by faults. [113] They correspond to about 2 and 5%, respectively, of the global volcanic flux of these compounds. [166], An alternating cycle of fumarolic activity, an accumulation of fumarolic gases in the conduit and lava dome, and explosive activity followed by renewed fumarolic activity have characterized Lascar's activity since 1984. [140], The lava domes interacted with glaciers, resulting in the formation of a glacier run whose deposits are found as far as 10 kilometres (6.2mi) from the volcano. The southeastern slopes drain into Laguna Leja[9] which is close to the volcano,[48] and the northwestern slope drains through the Quebrada de Morro Blanco. Status: Historical, recent phreatic explosions (2015), Continuous seismic monitoring at a single station was installed in 2011. [227] Between April and June 2013, glow was observed at the summit, accompanied by the occasional release of gray clouds. VW is a higher education, k-12, and public outreach project of the Oregon Space Grant Consortium [34] It probably formed when one of the craters filled with andesitic lava to the point of overflow. [197] The deposits and small structures, such as levees and lobes, were conserved by the dry climate in the region. Observers noted the formation of a cauliflower-shaped cloud that eventually developed into a mushroom cloud with a maximum height of 9.4 kilometres (5.8mi) above the volcano. Why do people study Geology? [89], The oldest volcanic activity at Lascar occurred between 220,000[6] and less than 50,000 years ago. [35] Flows from the first stage of Lascar's activity are exposed at its western foot,[54] while lava flows are buried beneath pyroclastic material on the eastern flank. [135] Possibly, the magma chamber of stage I had almost solidified when the injection of basaltic magma at depths of over 5 kilometres (3.1mi) triggered a remelting. At the time preceding the eruption, the magma chamber had a thermal stratification;[151] injections of mafic magmas had heated the magma chamber and induced convection. Add an answer . Lascar is an andesitic-to-dacitic stratovolcano with 3 overlapping summit craters. [144] Pumices are encased in the ignimbrite as lenses and levees and are also found in the terrain above the canyons. [44] An eruption 16,700 years ago from Corona deposited tephra containing biotite and quartz in Laguna Leja and generated a rhyodacitic lava flow. [53] The oldest mafic andesites are less than 43,000 years old, while the Chaile and Saltar pyroclastic flows erupted over 26,500 years ago. There were no injuries[211] or fatalities,[8] however the eruption did lead to water pollution in the region, including increases in cadmium, copper and lead concentrations in local rivers. On 20 February 1990, an eruption column rose 814 kilometres (5.08.7mi) above the crater,[57] resulting in ash fall over 100 kilometres (62mi) away from the volcano. [116] The release of gas by the magma is favoured by strong temperature contrasts between incoming magma and the magma chamber,[94] and processes occurring during the mixing may explain the high emission of sulfur dioxide by Lascar. On this Wikipedia the language links are at the top of the page across from the article title. [60] At the end of the eruption, a 1.5-kilometre-wide (0.93mi) caldera[137] and the two western craters formed. [47] Lava flows from this stage have thicknesses of 2060 metres (66197ft) and lengths reaching 5 kilometres (3.1mi). Today the volcanic complex consists of the dormant western edifice and the active eastern edifice, the latter comprising three overlapping craters. [164] This eruption was the most significant of the previous two decades,[163] having a VEI of 3. Panorama from the Lascar Southern pyroclastic flow. [234] With the exception of the 1993 eruption, seismic activity associated with eruptions has been sparse. What plate is forming lascar volcano? [67] Additional component minerals found at Lascar include anorthite, augite bordering on diopside, bronzite, fassaite, forsterite, hypersthene, pigeonite and more. An eruption event known as Piedras Grandes was followed by the large Soncor eruption. During earthquakes which type of fault results when one plate is compressed up onto . [38], Lascar is located in the main volcanic arc, on the western margin of the Altiplano. [148] The total volume of the Soncor eruption products has been estimated to be either 5.6 cubic kilometres (1.3cumi) dense rock equivalent or 10 cubic kilometres (2.4cumi) net volume, both minimum estimates. The volcanic complex experienced several major, up to VEI 6, pre-historic eruptions but no calderas were formed. [134], Later volcanic activity buried this edifice beneath thin pyroclastic flows. Lascar Volcano Volcanic Ash Advisory: ISOLATED PUFF AT 1545 to 27000 ft (8200 m) Thu, 3 Feb 2022, 00:26 Lascar (Chile) - Smithsonian / USGS Weekly Volcanic Activity Report for 26 January-1 February 2022 (NEW) SERNAGEOMIN reported minor increases in surficial activity at Lscar. [220], Further activity occurred in May 2005, with a 810-kilometre-high (5.06.2mi) ash cloud, and in April 2006. [193] The pyroclastic flow surfaces subsided after the eruption, with pulses of faster subsidence coinciding with the 1995 Antofagasta earthquake and the 2007 Tocopilla earthquake. [110] There are temporal variations in the output: after a decrease in 2009, sulfur output increased in 2012, probably as a consequence of the arrival of new magma at depth. [215] The collapse structures during this activity were larger than those noted in previous activity, possibly because the April 1993 eruption had emptied part of the system. [134] It is white, heterogeneous[90] and mostly featureless with only weak sorting,[144] but features a noticeable compositional zonation. On the southeastern flank, the pyroclastic flows formed a fan extending several hundred metres into Pampa Leija. Explosive activity presumably occurs when gases can no longer escape. [7] A number of earthquakes were recorded in early February 2012. [29] The eruption was also observed by geologists in Toconao,[164] where the explosion was violent enough to wake up people who were sleeping. It features well developed levees and a 10-metre-thick (33ft) flow front. [34] This lava flow is known as the TumbresTalabre lava flow; its margins are 1040 metres (33131ft) high, and it features a central channel.
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