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. Further, fractures permitting gas passage are obstructed when the magma contracts. [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. According to SEGEMAR the pyroclastic flows traveled short distances to the N and SE. 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). 2017-01-13 18:27:12. [247] In 1993, yearly precipitation at several towns around Lascar ranged from 2.5 to 20.1 millimetres (0.098 to 0.791in). Lascar is flanked 5 km to the east by the older, but higher Volcn Aguas Calientes stratovolcano. [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. [56] The eruption released about 400,000 tonnes (390,000 long tons; 440,000 short tons) of sulfur dioxide, about half the quantity released by the 1980 eruption of Mount St. Helens,[207] and was sufficient to cause a noticeable increase in atmospheric opacity. [39] An alternative dating scheme considers Chaile to be 47,000 16,000 years old and Saltar 167,000 9,000 years old. [130] The long-term magma supply rate of Lascar is about 0.08 cubic kilometres per millennium (80,000m3/a),[131] the volcano has produced about 3040 cubic kilometres (7.29.6cumi) of rock. Explosive eruptions are the greatest hazard at Lascar. It is the most active volcano in the region, with records of eruptions going back to 1848. 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. [174] The strongest pulse occurred on 20 April between 6:28 and 9:20 and sent flows towards the northwest. This way, topographic details can be scanned over large areas with great precision and in relatively little time. [38], Lascar is located in the main volcanic arc, on the western margin of the Altiplano. [190], There is a pronounced morphology characterized by a channel upslope and snout-like toes downslope. Imprecise argonargon dating on younger andesites has yielded dates of 14,000 18,000 and 17,000 22,000 years. Lascar is the most active volcano in the central Andes. [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. [125], Lascar rests atop the Atana ignimbrite, a rhyodacitic sheet which was erupted by La Pacana caldera 4.53.7 million years ago. [238] It publishes a volcano alert level for Lascar and has created a volcano hazard map for the volcano. [78] SiO2 concentrations range from 55.5 to 67.8% by weight, and the rocks have medium to large concentrations of potassium. [249] 8,500 years ago, the climate in the region became much drier, and the amount of erosion decreased substantially. 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. It is about 800 m in diameter and 300 m deep. [239] Past eruptions caused ash fall in Argentina and disruption of air travel[241] and could have major effects in the Salta Province in case of renewed activity. [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. [35], About 30% of these flows were formed by ash and 70% by blocks,[174] with larger fragments accumulating on the margins of each flow deposit. Wiki User. [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. A seismic monitoring experiment was realized in 2008. [57] Recorded eruptions occurred in 1858, 1875, 18831885, 18981900(?) Transform plate boundaries are where plates slide laterally past one another, producing shallow earthquakes but little or no volcanic activity. Light, dark, and banded pumice are mixed in this flow. [72] At least four alignments of volcanoes are recognized in the region. [88] Magma petrology implies that there is another reservoir at 6 kilometres (3.7mi) depth. The whole volcano did not deform during the eruption sequence. [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. The unit is about 2 kilometres (1.2mi) wide[135] and consists of large blocks encased in ash. [43][49] Cerro Corona gets its name from a crown-shaped structure at its top. [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. [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. Walter, Light detection and ranging (LiDAR) is based on the measurement of the time delay between the emission of a laser pulse and the reception of the echos that return from target objects. [78] This occurs because as the magma loses its gas content, the number of pores in it, and thus its permeability to gas, decreases. [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. [34] In the centre of the westernmost crater lies a smaller crater, 250 metres (820ft) deep and 300 metres (980ft) wide. [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 Ring of Fire is a direct result of plate tectonics: specifically the movement, collision and destruction of lithospheric plates (e.g. Carbon in the gases may come from skarn assimilation. [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. [90] The Piedras Grandes unit is over 26,500 years old,[39] possibly between 63,000 and 100,000 years old. [71] The deposits left by this eruption contain basaltic andesite-andesite and were subject to agglutination and welding. The fumaroles also release carbon monoxide, hydrogen, hydrogen chloride, hydrogen sulfide, and smaller amounts of helium. [27] They are constructed on a crust that is between 50 and 70 kilometres (31 and 43mi) thick. [196] Additional surfaces were covered by ash cloud surges, reaching thicknesses of no more than 5 centimetres (2.0in) on the sides of the pyroclastic flows. [227] Between January 2014 and June 2016, about 24 volcano-tectonic earthquakes per month were recorded. [183] The southern flank flows at first proceeded along a gully before spreading out. Another explosion at 13:02 sent a column 8.5 kilometres (5.3mi) high. [72], Hydrogen chloride and hydrogen fluoride are also released in large amounts, with estimates made in 20032004 indicating a mass flux of 340,000,000 kilograms per year (11kg/s) and 150,000,000 kilograms per year (4.8kg/s) respectively. [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. Geoth. [51] This dacitic lava was erupted on Lascar at high altitude and has a blocky surface. [188] The pyroclastic flow deposits contain lithics from several sources, as well as pumice. [90], Temperatures of the magma chamber range from 890970C (1,6301,780F); the mafic magmas that are injected in the chamber are about 150200C (270360F) hotter than the extant andesite and dacite. The large eruption gave rise to a pyroclastic flow that extended 27 kilometres (17mi) westward and contained breccia and various magmas. Explosive activity presumably occurs when gases can no longer escape. Image: @AlexisBolbaran/Twitter. Lascar is just left of Aguas Calientes, which is the central cone. Panorama from the Lascar Southern pyroclastic flow. [177], The eruption columns underwent several collapses, creating pyroclastic flows at least seven to nine times. [156] The deposits left by this erosional period contain no clear evidence of stage III activity; indeed Lascar was probably inactive between 14,000 and 10,500 years ago. [140] The Soncor magmas were associated with a volatile phase that underwent extensive interaction with the future eruption products. [182] Hot pyroclastic flows on the southeastern flank covered a surface area of 1318.5 kilometres (8.111.5mi). Which volcano to choose? [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. Learn. [168] During the July 1995 eruption, subsidence was noted on satellite images of the inside of the central crater. Match. We're aiming to achieve uninterrupted service wherever an earthquake or volcano eruption unfolds, and your donations can make it happen! [89] There appear to be two distinct chamber systems, an andesitic one that is responsible for the frequent andesite lava and pyroclastic flow activity, and a dacitic one that was involved in the Piedras Grandes and Soncor activities. [64] The total volume of these pyroclastic flows is about 0.06 cubic kilometres (0.014cumi). Match. In this remote territory, where eruptions are poorly recorded, many volcanoes are higher than 6,000 metres (20,000ft). Terms in this set (10) Active volcano. [180] Ash from this eruption was identified in ice cores from Illimani[200] while sulfates reportedly appeared in ice taken from the Arctic and Antarctica. Written By. Aguas Calientes in the middle; Lascar on the left. [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. It is an andesitic to dacitic stratovolcano with six overlapping craters, trending roughly northeast, with the active, fuming crater located near the center. Today the volcanic complex consists of the dormant western edifice and the active eastern edifice, the latter comprising three overlapping craters. Test. What plate is forming lascar volcano? [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. [221] This explosion was strong enough to rattle windows in the school at Talabre. 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. At least nine units form the Saltar deposit, with the northern flows displaying flow welding. [34] It probably formed when one of the craters filled with andesitic lava to the point of overflow. In South America, a safety warning was issued by Chilean officials after the Lascar volcano erupted a giant cloud of smoke comprising of volcanic ash and hot gases up to twenty thousand feet into the sky on Saturday. [129] The Observatorio Volcanolgico de los Andes del Sur in Temuco also employs webcams to watch Lascar. [26] Tertiary sediment and volcanic rocks can also be found. This pulse generated an eruption column 23 kilometres (14mi) high. [231] In December 2022, an explosion generated a 6 kilometres (3.7mi) high plume. [141] The Plinian deposit has a colour ranging from white to creamy. 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. Landforms over this basement include ignimbrites, lava domes, and stratovolcanoes. Dacite has more plagioclase and rhyolite. [245] High nickel concentrations in crops from Talabre appear to be caused by volcanic activity as well. [153] Such a vent or caldera is substantially smaller than the volume of rocks erupted, a discrepancy that is also evident in the 1932 eruption of Quizapu. Subsequently, a number of fumaroles were active around the crater. [164] This eruption was the most significant of the previous two decades,[163] having a VEI of 3. [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. [197] The deposits and small structures, such as levees and lobes, were conserved by the dry climate in the region. [6][29] Guallatiri, for example, features fumarolic activity that is visible in satellite images. Lascar is on the centre-left, Aguas Calientes right. [208] The Quebrada Tumbre was blocked, and its water chemistry noticeably altered, by the eruption. [2], Seismic activity occurs at Lascar. [9] Lahar deposits are found in adjacent valleys, suggesting that wetter periods had occurred during Lascar's activity.
Paediatric Neurologist Portland Hospital, Articles L