[59] An eruption commenced at 11:35 local time on 18 April 2006. Match. [55] The extinct western cone (also known as Apagado) is composed of layers of lava and pyroclastics. For some eruptions, including the January 1854 eruption, it is not clear whether they occurred at Lascar or Aguas Calientes,[157] and some early reports of volcanic activity at Aguas Calientes probably refer to Lascar. [174] The strongest pulse occurred on 20 April between 6:28 and 9:20 and sent flows towards the northwest. [16] A number of supervolcanoes exist in the Central Volcanic Zone, they are part of the Altiplano-Puna volcanic complex. [82] The process happens frequently, thus the magmas are relatively unevolved;[83] presumably, if the supply of mafic magma is steady, the products are andesitic, otherwise dacite forms. At least nine units form the Saltar deposit, with the northern flows displaying flow welding. Because Lascar is located in a remote area, it is monitored primarily by remote sensing. [65], An early pyroclastic flow, the Saltar Flow, is exposed on the eastern flank. The magma supplied to the volcano ultimately comes from the subduction of the Nazca Plate beneath the South America Plate. Another debris flow from Corona spread towards Salar de Atacama. [143] The deposits are formed by a Plinian fallout deposit and an ignimbrite rich in lithics. Terms in this set (10) Active volcano. [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. This sulfur extraction was facilitated by the high oxygen content of the magma, which allowed the formation of sulfur dioxide. Image: @AlexisBolbaran/Twitter. [6][29] Guallatiri, for example, features fumarolic activity that is visible in satellite images. Grey pumice deposits from the 1993 eruption are visible in the photo above, and the margins of some pyroclastic flows can be seen at right center. Hornfels, skarn, and rocks that are part of Lascar's lava dome ridge are the source of these xenoliths. Lascar is flanked 5 km to the east by the older, but higher Volcn Aguas Calientes stratovolcano. [139] The magmas were formed from a remelted proto-pluton that had been heated and resupplied with volatiles by mafic magmas. [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 17 December 1993, another explosion created an eruption column 810 kilometres (5.06.2mi) high. [44] The end of glaciation may have accompanied an increase in volcanic activity, a phenomenon that has been noted at other volcanoes. [56] Measurements made from 1961 to 1997 determined that the eastern crater is 1 kilometre (0.62mi) wide and 150200 metres (490660ft) deep[57] and thus the largest,[53] the central crater is 600 metres (2,000ft) wide and 100200 metres (330660ft) deep, and the western crater is 800 metres (2,600ft) wide and 200300 metres (660980ft) deep,[57] increasing to 400 metres (1,300ft) depth in 20052006. Lascar is a stratovolcano in Chile within the Central Volcanic Zone of the Andes, a volcanic arc that spans Peru, Bolivia, Argentina and Chile. [157] The 1933 eruption was seen as far away as Chuquicamata. Flashcards. 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. [128][47] Most present-day activity consists of the release of fumarolic gas with additional vulcanian activity that generates eruption columns several kilometres high,[129] typically every three or two years[128] and half of the time during austral spring[7] as well as active deformation of the three active craters observed in interferometric synthetic-aperture radar. [129] In March 1990, the lava dome had a temperature of 100200C (212392F), with some parts exceeding 900C (1,650F). [177], The eruption columns underwent several collapses, creating pyroclastic flows at least seven to nine times. 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. [248], During the glacial periods, the volcano most likely featured small glaciers. The unit is about 2 kilometres (1.2mi) wide[135] and consists of large blocks encased in ash. Four eruptions occurred at 15:20, 17:22, 19:00 and 21:00 UTC, forming eruption columns reaching altitudes of 10 kilometres (6.2mi). [107][108] In 2005, Lascar was the third-largest source of volcanic sulfur dioxide in the world among continuously active volcanoes, behind Etna in Italy and Bagana in Papua-New Guinea. It has a volume of 56 cubic kilometres (1.21.4cumi). [12] However, the inhabitants of the town of Camar consider Lascar a protective mountain spirit[13] and in Susques (Argentina) it is believed that snow will fall if Lascar is steaming strongly. [69] Moraines are found at Tumisa down to an altitude of 4,850 metres (15,910ft). A convergent boundary. Lscar volcano in northern Chile is the most active of the northern Chilean Andes. Two types of Plate boundaries are often associated with volcanic eruptions: Plates rip apart at a divergent plate boundary, causing volcanic activity and shallow earthquakes; and At a convergent plate boundary, one plate dives or "subducts" beneath the other, resulting in a variety of earthquakes and a line of volcanoes on the overriding plate. The plates are so close to each other that they start to mash together, and this causes the Earth's mantle to escape from the Earth. The largest eruption of Lascar known to recorded history occurred in April 1993 and caused ash fall as far away as Buenos Aires. [58] The craters show evidence that activity has migrated westward. [36][44] Other basement rocks are the sandstone-containing marine DevonianCarboniferous Lila formation, the red-orange Permian Cas formation containing volcanic rocks and granites,[21][37] as well as the volcanic PermianTriassic Peine formation and Cerro Negro strata, which also contain intruded rocks and lake sediments. [6] The present-day snowline in the region lies at an altitude of 6,050 metres (19,850ft), higher than the summit of Lascar. Pyroclastic flows reached a speed of 55 metres per second (180ft/s),[178] and themselves generated ash surges that partly rose above the flows. Afterwards, up to four different units of pyroclastic flows, each 110 metres (3.332.8ft) thick, formed deposits up to 10 kilometres (6.2mi) long. [102], Release rates of SO2 amounted to 27 tonnes per day (0.31kg/s) in 1989,[103] and 28 tonnes per day (0.32kg/s) in 2003. [245] High nickel concentrations in crops from Talabre appear to be caused by volcanic activity as well. [114] Finally, Lascar is vigorous producer of sulfate dust particles,[113] which are released at a rate of about 100,000 trillion particles per second. [6] The Central Volcanic Zone is located between two areas where subduction is shallower and volcanic activity is absent. 92 views 3 minutes ago In Chile, the Lascar volcano unexpectedly erupted on December 10th, sending a plume of ash more than 6,000 meters or 19,700 feet above what was already one of the world's. [36] The valleys drain the western, northern and southwestern slopes of Lascar. Get started for FREE Continue. See the station distribution here and the data availability here. [203], This eruption was the most significant eruption of Lascar in the last 9,000 years, with a volcanic explosivity index of 4[35][129] and a duration of 32 hours,[8] and one of the most significant volcanic eruptions in the recent history of Chile. [36][70] The Miscanti Line dissects the Quaternary basement beneath Lascar,[71] and it may be a hinge of a fold that is being propagated by faults. [157][53] This flow extends 8 kilometres (5.0mi) northwest and is 2030 metres (6698ft) thick. It probably started shrinking in April 1992, although the shrinkage was directly visible only in November. [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. These include gas monitoring, seismometers, a weather station and cameras. The importance of the multidisciplinary approach. Hikers were near the crater and took video of the eruption. During minor explosive eruptions, eruption columns reach heights of up to 5,000 metres (16,000ft). Lascar is the most active volcano in the central Andes. [43] The Pampa Chamaca and Tuyajto ignimbrites are somewhat younger, 2.62.2 million and less than 1 million years respectively. 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. [129] The Observatorio Volcanolgico de los Andes del Sur in Temuco also employs webcams to watch Lascar. [104], Gases are partly supplied from shallow magma; the volume of magma erupted is too small to contain all the exhalations. [68] Traces of glacial action are found on the older parts of Lascar at altitudes above 4,600 metres (15,100ft) and include meltwater gorges, striated rock surfaces, and U-shaped valleys. Volcanic activity is characterized by constant release of volcanic gas and occasional vulcanian eruptions. During earthquakes which type of fault results when one plate is compressed up onto . The volcanic complex experienced several major, up to VEI 6, pre-historic eruptions but no calderas were formed. [123] Electrical conductivity data suggest that a hydrothermal system exists beneath Lascar,[124] but the existence of such a system has been questioned. [117] The presence of argon and nitrogen in low-temperature fumaroles indicates that air is involved in their formation,[100] although a portion of each of these two gases is non-atmospheric. Imprecise argonargon dating on younger andesites has yielded dates of 14,000 18,000 and 17,000 22,000 years. [225] The eruption ended around 15:32 on 20 April,[222] although some explosions occurred in the following days. VW is a higher education, k-12, and public outreach project of the Oregon Space Grant Consortium The Soncor magma chamber may have been too deep to collapse when it was emptied, explaining why no significant caldera was formed. [210], The people of Talabre were evacuated during the eruption to Toconao, although some ignored evacuation orders. [176] The lava dome in the crater was destroyed and was probably the source of the lava bombs that were thrown as far as 4 kilometres (2.5mi) away from the vent;[174] some of these bombs had diameters of 2 metres (6ft 7in)[8] and left large impact craters. Lascar has been active since at least 56,000 years ago, though some argue for activity beginning 220,000 years ago. Learn. [175] Lithic blocks are up to 3 metres (9.8ft) thick. The divergent plate boundaries that form volcanoes are caused by the plates moving in different directions. [39], The Tumbres eruption occurred around 7250 BCE,[157] commencing with the eruption of pumice falls that reach thicknesses of less than 1.2 metres (3ft 11in). [191] Flow surfaces display pronounced fractures with a V profile,[192] which developed a year after the eruption. [112] Sulfur is released from areas all over the cone, resulting in a noticeable sulfur smell. This unit, formed during stage II, is known as Piedras Grandes,[53]and is exposed on the western slopes below about 4,900 metres (16,100ft) altitude. [53] Activity has alternated between the eastern and western part of the volcano during its history. Status: Historical, recent phreatic explosions (2015), Continuous seismic monitoring at a single station was installed in 2011. Finally, the andesitic pumice Tumbres flow is found on the northwestwestsouthwestern slopes of Lascar. [199] Tephra fall from this eruption was recorded in Argentina, including in Buenos Aires, 1,500 kilometres (930mi) away, and in Brazil, Paraguay, and Uruguay. To the left, in the background, the. The Alert Level remained at Yellow (the second lowest level on a four-color scale) and the public were warned to stay at least 5 km away from the crater. [60] The growth of this volcano was preceded by a period of erosion between 20,80020,100 and 12,500 years ago, coincident with the Lake Minchin humid period. [47] In these valleys, the ignimbrite can be as much as 60 metres (200ft) thick. Volcanoes are most common in these geologically active boundaries. [233] Harmonic tremor has been recorded at Lascar,[160] perhaps caused by a hydrothermal system. [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. 2017-03-03 22:36:33. These ignimbrites form a 3 steep slope in the area. The San Andreas Fault Zone is not the only active transform plate boundary with U. S. National Park Service sites. [27] They are constructed on a crust that is between 50 and 70 kilometres (31 and 43mi) thick. It was accompanied by a Plinian fall deposit. Saumya joshi. [67], The stage II activity was accompanied by the eruption of block and ash flows consisting of andesite, and an eruption whose deposits include blocks with sizes of 15 metres (49ft). The first known activity occurred at the eastern cone and was characterized by lava flows, before shifting to the western cone where lava domes were emplaced. [57] Recorded eruptions occurred in 1858, 1875, 18831885, 18981900(?) It is the most active volcano in the region, with records of eruptions going back to 1848. [113] They correspond to about 2 and 5%, respectively, of the global volcanic flux of these compounds. High quantities of arsenic have been observed in local crops. [59], Layers of lava and pyroclastics are discernible in the craters. [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. There are traces of a collapse of the volcano towards the northeast, with an associated horseshoe-shaped scar. 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. SERNAGEOMIN reported that an eruption at Lscar began at 1236 on 10 December with an explosive event that produced a dense ash plume and pyroclastic flows proximal to the crater. Add an answer. [59][97] In December 2002, two fumaroles had temperatures exceeding 295C (563F). [47] Originally considered part of stage III, it was more recently attributed to stage IV given the considerable (6,000 years) temporal gap between the Tumbres eruption and stage III volcanism, and the geochemistry of the rocks. [180] Explosive eruptions, accompanied by the formation of eruption columns reaching heights of several kilometres, sometimes leading to ash fall in Jujuy, Argentina, occurred on 27 February 1994; in July 1994, November 1994, and March 1995; and on 10 May, 20 July and 18 October 1996. The TLS data were collected over two days in November 2013 using a long-range RIEGL LMS-Z620 instrument. [45] An area of increased electrical conductivity has been identified beneath Lascar and extends to some neighbouring volcanoes, reaching a depth of over 6 kilometres (3.7mi) south of Lascar. How to watch volcanoes? Acamarachi is the white cone on the right. [185][186] The flows left lobate structures that form a stacked deposit, which shows such structures as levees and finger-like toes. The Branches of Geology and Career 4. [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. The case of June 13th, 2015 Ojos del Salado false volcanic eruption", "Trends in the nonvolcanic component of stratospheric aerosol over the period 19712004", "Identificacin de fases portadoras y flujos de mercurio en el registro sedimentario de la Laguna del Plata, regin central de Argentina", "SERNAGEOMIN da a conocer nuevo ranking de volcanes", "Red Nacional de Vigilancia Volcnica de Chile", "El riesgo de desastres en la planificacin del territorio", Ministry of Federal Planning, Public Investment and Services, "How will melting of ice affect volcanic hazards in the twenty-first century? [91], Lascar emits plumes of gas and white clouds of condensed water vapor,[29] mostly over many hundreds of fumarolic vents, which are chiefly located in the active crater. Both plates are capped by oceanic crust. [39] An alternative dating scheme considers Chaile to be 47,000 16,000 years old and Saltar 167,000 9,000 years old. The next day, additional explosions occurred at 15:04, 15:05 and 17:39 UTC, with a maximum column height of 7 kilometres (4.3mi). Why It Matters: Science of Geology 2. Lascar is an andesitic-to-dacitic stratovolcano with 3 . [36] This limestone formation has been identified as the Yacoraite formation. They occur beneath altitudes of 4,100 metres (13,500ft), their vents buried by later activity. [35] With a surface area of 54 square kilometres (21sqmi), the volcano has a volume of 15 cubic kilometres (3.6cumi). [239] Explosive eruptions and ash falls are the major threat to humans from Lascar. The largest historical eruption of Lascar took place in 1993, producing pyroclastic flows to 8.5 km NW of the summit. Data available through GEOFON. Blog. [171], Vulcanian explosions started on 18 April 1993, and on 1920 April 1993, a major eruption occurred. [248], Volcanic activity at Lascar affects neighbouring ecosystems such as the Aguas Calientes crater lake and Laguna Lejia; flamingos disappeared from the latter after the 1993 eruption and did not return until 2007. [25][26] The Central Andes contain many hundreds of volcanoes, extending over the countries of Argentina, Bolivia, Chile and Peru. [32], Lascar is located in the Antofagasta Region of Chile,[31] and is 5,641 metres (18,507ft),[33][3][34] 5,592 metres (18,346ft),[31][21][15][1] or 5,450 metres (17,880ft) high, according to different sources. SERNAGEOMIN reported that seismic signals characterized as moderate were recorded on 19 December and located near Lscar's main crater at shallow depths. [36] The lavas from stage I are mostly exposed north and west of Lascar. Test. [86] After the end of stage I, a period of glacial erosion occurred prior to new activity,[72] which created furrows in the Saltar flow. [35] At least ten different pulses were observed, generating columns of various heights[173] and forming mushroom clouds. [249] 8,500 years ago, the climate in the region became much drier, and the amount of erosion decreased substantially. [34] The westernmost of these three eastern craters is the currently active one, surrounded by rims that reach heights of 150 metres (490ft). [3] Immediately east of it lies the eastern cone, which is contiguous with the western cone. [36] Geographically, the area of Lascar is located between the Altiplano and the Salar de Atacama[21] 30 kilometres (19mi) farther west;[37] the terrain at Lascar dips in the direction of the Salar. [201] Over 0.1 millimetres (0.0039in) of ash fell over a surface area of over 850,000 square kilometres (330,000sqmi). In this remote territory, where eruptions are poorly recorded, many volcanoes are higher than 6,000 metres (20,000ft). An eruption event known as Piedras Grandes was followed by the large Soncor eruption. As of 2012[update], it had a population of 50 inhabitants. The fumaroles also release carbon monoxide, hydrogen, hydrogen chloride, hydrogen sulfide, and smaller amounts of helium. At what boundaries do volcanoes form? 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. [182] Hot pyroclastic flows on the southeastern flank covered a surface area of 1318.5 kilometres (8.111.5mi). [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. [30] Also fumarolically active are: Sabancaya, El Misti, Ubinas, Tacora, Isluga, Irruputuncu, Olca, Ollague, San Pedro, Putana and Lastarria. [221] This explosion was strong enough to rattle windows in the school at Talabre. Global Volcanism Network, Smithsonian Institution, Washington, D.C. VW is a higher education, k-12, and public outreach project of the Oregon Space Grant Consortium Also, a volcano that is not presently erupting, but that has erupted within historical time and is considered likely to do so in the future. The volcano sent "an eruptive column" of volcanic ash and hot gases 6,000 metres above its crater, the service said. [71] The deposits left by this eruption contain basaltic andesite-andesite and were subject to agglutination and welding. [153] The Capricorn Lava overlies the Soncor deposits. 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. [67] Additional component minerals found at Lascar include anorthite, augite bordering on diopside, bronzite, fassaite, forsterite, hypersthene, pigeonite and more. . Add an answer . [246], The area around Lascar is one of the driest and highest volcanic settings in the world. Flashcards. [27] Given the low population density around many of these volcanoes, there is often little information on their activity. Light, dark, and banded pumice are mixed in this flow. Regulatory limits on concentrations of other elements in water were also exceeded, although only temporarily. The Ring of Fire is a direct result of plate tectonics: specifically the movement, collision and destruction of lithospheric plates (e.g. Metasomatism does further affect rocks derived from magma chamber walls. [54] The Soncor flow is found primarily on the western side of Lascar, with part of it also southeast of Lascar. stratovulcano 5592 m / 18,346 ft. Northern Chile, -23.37S / -67.73W. [60] At the end of the eruption, a 1.5-kilometre-wide (0.93mi) caldera[137] and the two western craters formed. [132], Activity subsequently shifted to the eastern edifice. It is an andesitic to dacitic stratovolcano with six overlapping craters, trending roughly northeast, with the active, fuming crater located near the center. 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). [229] This eruption may have been triggered by a precipitation event which added water to the volcan's hydrothermal system. What plate is forming lascar volcano? [54] Exposures of the basement are often delimited by faults. [63] A 6-kilometre-long (3.7mi) lava flow on the northern flank reaches almost to the village of Talabre. Bunch grass and shrubs grow on the volcano's slopes. [156] The frequent smaller explosive events commonly occur unexpectedly and can thus endanger people on the mountain. [85] The overall magma supply rate of Lascar is 0.020.03 cubic metres per second (0.711.06cuft/s). The flow deposit was later modified by glacial activity. A major eruption occurred at the Lascar Volcano. Preceding historical eruptions did not exceed 2. Large lava flows are visible on its NW flanks. [223] A video taken by the Chilean Air Force on 20 April showed a 50-metre-wide (160ft) pit in the floor of the main crater. Glowing was also reported in October and November 2013. [104] Overall sulfur output ranges between 200 and 2,300 tonnes per day (2.3 and 26.6kg/s). Lascar vulcano. [181] Lascar's activity has been monitored by Thematic Mapper, which has been used to monitor volcanic activity since 1985, when hot spots were observed on Lascar. [63] The formation of the first cone at Lascar may have been facilitated by the intersection between the Miscanti Line and another eastwest lineament[72] formed by PliocenePleistocene tectonic compression of the region,[73] and the lineament would have worked as an ascent path for magma. Other volcanic centres are also located on this line,[54] including the Corona and Saltar lava domes, and the Miscanti and Lejia volcanoes. [161] Another series of eruptions occurred between November 1951 and January 1952; one eruption is recorded from 1940. It is about 800 m in diameter and 300 m deep. Today the volcanic complex consists of the dormant western edifice and the active eastern edifice, the latter comprising three overlapping craters. [101] The fumarole gases react with surrounding rocks, forming precipitates and altered rocks. http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=-23.37%20-67.73&aq=&, http://www.google.com/search?hl=en&biw=1362&bih=600&gbv=2&site=search&tbm=isch&s, http://scholar.google.com/scholar?hl=en&q=L%C3%A1scar%20Volcano&as_allsubj=some&. [77], The rocks of Lascar belong to the calc-alkaline series. [83] This origin of Lascar magmas is reflected in the textures of rocks. Subsequently, a number of fumaroles were active around the crater. [45] Noticeable erosion occurred in the areas over which pyroclastic flows had passed, forming abrasion surfaces and removing loose detritus from the ground. [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.