villarrica volcano plate boundary

 

After a long period of fumarolic activity, a series of explosions that began on 19 September at 2200 ejected ash from the main crater. Information Contacts: Gustavo Fuentealba1 and Paola Pena, Observatorio Volcanologico de los Andes del Sur. After ash emissions during July 2018 and an increase in of thermal activity from late July through early September 2018 (BGVN 43:10), Villarrica was much quieter through February 2019. During an overflight on 16 February, supported by ONEMI, volcanologists observed the lava lake and recorded temperatures near 800 degrees Celsius, tephra in and around the active crater, and a diffuse layer of ash on the flanks. Similar eruptions occurred on 16, 17, and 21 August. By night, a red glow over the summit indicates that a lava fountain is filling the crater. A second emission was recorded on 18 July;the Sentinel-2 satellite recorded the largest summit thermal signature since 10 December 2017 the same day. The bottom of the crater appeared about 4 m higher than it was on 26 September 2017, and the vent diameter had expanded by 2 m. Ash and lapilli fragments were found around the edge of the crater on 15, 22, and 25 October. Thousands of people evacuated from within a 10-kilometer (6-mile) radius of Villarrica. Gas emissions were visible in the daytime. Activity during 2016. The parallel fumarolic activity was moderate and mainly consisted of vapor. As of 20 September, an increase in seismicity occurred at stations VNVI and CVVI while gas and steam emissions ceased, and the usually persistent fumarole disappeared. A research effort in mid-March 2018 by Liu et al. Small collapse pit adjacent to main pit is visible … 2018: March An explosive event at 0051 on 8 November ejected incandescent material and produced a plume that rose 220 m. A gas-and-ash emission at 1814 on 10 November rose 320 m and drifted SSW. Tremor, mild explosions, and a new pyroclastic cone. Ash and lapilli were visible in satellite imagery on the eastern edges of the crater. and drifted N, NE, E, and ESE. As a result, tectonic settings determine the types of volcanoes that form and the types of eruptions that take place. At the very bottom center an opening exposed ~20 m of material with a bright red glow. Long-period (LP) events were recorded by the seismic network at 1146 and 1156 on 16 February. On 3 February, the crater floor was partially covered with talus, but a small vent was actively degassing in the N part of the crater floor. On 24 September at 0800 fine ash was ejected briefly, covering Villarrica's snowy slopes. Fine ash deposited on the N and NW flanks during 16-17 September was attributed to wind moving ash from within the crater, and not to new emissions from the crater (figure 88). Crater incandescence was visible on 23 July. | December Historical eruptions at Chile's Villarrica, documented since 1558, have consisted largely of mild-to-moderate explosive activity with occasional lava effusion. The Buenos Aires VAAC reported water vapor and light ash emissions to 3 km beginning 22 March, drifting 45 km SE and continuing intermittently through 25 March. SERNAGEOMIN noted a minor variation in the baseline of the inclinometers; continued monitoring indicated the variation was seasonal. Deformation data suggested minor inflation. Contr Mineral Petr, 103: 361-386. Incandescence was observed in the opened upper portion of the sub-vertical chimney. From 9-22 July, tremor detected by the VN2 seismic station, 4 km NW of the summit, increased (figure 26). Incandescent material from lava fountaining ejected above the crater rim was periodically visible on 16 July. Significant thermal anomalies from continued Strombolian activity at the lava lake and small ash emissions persisted through October 2016 (BGVN 41:11). Incandescence was not detected. The average effusion rate was estimated to be ~0.45 m3/s during 24 October-1 November. According to Projecto Observación Visual Volcán Villarrica (POVI), satellite images of Villarrica acquired on 25 July revealed a weak thermal anomaly. SERNAGEOMIN reported that a long-period (LP) event and associated explosion were recorded by Villarrica’s seismic network at 1041 on 23 October. Geochemistry, Geophysics, Geosystems, 20. https://doi.org/10.1029/2018GC007692. The crater did not show any explosive activity, indicating slow uplift of basaltic lava with low gas contents. The Alert Level remained at Yellow, the second lowest level on a four-color scale. Pulsating emissions of water vapor were common. J. Volcanol. Analysis of MODIS (Moderate Resolution Imaging Spectroradiometer) band 21 (3.929-3.989 μm) satellite images from 2003 to 2013 highlights three main cycles of activity. Continuous incandescence was observed in webcams during August 2018; satellite thermal data identified an abrupt rise in thermal energy in late July that remained at a low level into early September 2018. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://hotspot.higp.hawaii.edu/; http://modis.higp.hawaii.edu/); Buenos Aires Volcanic Ash Advisory Center (VAAC), Servicio Meteorológico Nacional-Fuerza Aérea Argentina, 25 de mayo 658, Buenos Aires, Argentina (URL: http://www.smn.gov.ar/vaac/buenosaires/inicio.php?lang=es); MIROVA (Middle InfraRed Observation of Volcanic Activity), a collaborative project between the Universities of Turin and Florence (Italy) supported by the Centre for Volcanic Risk of the Italian Civil Protection Department (URL: http://www.mirovaweb.it/); Cristian Gonzalez G., flickr (URL:https://www.flickr.com/photos/cg_fotografia/), photo used under Creative Commons license (https://creativecommons.org/licenses/by-nd/2.0/). Internatl Symp Volc Andean & Antarctic Volc Problems Guidebook, Excur D-3, 56 p. Moreno H, 1993. Crater incandescence was visible later that day. LearninG objectives Students will be able to compare and contrast volcanoes at convergent and divergent plate boundaries. This situation was continuing as of 25 November, with a small gap in mid-late November. Inner crater pit completely visible without incandescent lava. 39.42 S, 71.93 W summit elevation 2847 m stratovolcano . Res., v. 113, p. B08206, doi:10.1029/2007JB005328. Continuous explosions with tephra emissions and some black pyroclastic flows over the ice-covered slopes have been observed. During this reporting period, comparative quiet prevailed. They also reported on NASA ASTER IR observations of a progressive increase in spectral brightness in satellite data on 10 and 26 November and 3 December. The 4-hour sequence was interpreted as magmatic injections leading to gas-charged explosions. During the first two weeks of January 1997, incandescent lava returned to the central pit (BGVN 21:12). That night and through the following morning, however, the volcano emitted a small ash-and-gas plume that drifted ENE toward the community of Chinay-Palguín. Last known eruption: The current eruption has been ongoing since December 2014. According to ONEMI about 3,600 people were evacuated from a 10-km-radius of the volcano. The surface of the lava lake, last seen on 19 January, remained low (~200 m below the crater rim). Strombolian explosions from the crater were observed on 26 September, and tephra deposits on the E edge of the crater were noted. A flyover by the Oficina Nacional de Emergencia - Ministerio del Interior (ONEMI), the National Emergency Office of the Ministry of Interior and Public Safety, on 17 December was not able to observe the bottom of the crater due to weather conditions. Francisco Salazar 01145, Casilla 54-D, Temuco, Chile. Based on web camera views, the Buenos Aires VAAC reported that on 7 February diffuse gas-and-steam plumes rose from Villarrica and quickly dissipated. Another long-period event and explosion were recorded at 1829 later that day that generated another ash plume, though weather clouds obscured views. On 26 October 2008, according to the Observatorio Volcanológico de los Andes del Sur-Servico Nacional de Geologia y Mineria (SERNAGEOMIN), three gray plumes containing a small amount of ash were discharged from the main crater and rose 100 m above the crater rim. Crater observations for the interval 11 September 1996-13 January 1997. The Buenos Aires VAAC reported a 5.5-km-high ash plume on 27 March extending 55 km NE. By 17 January fissures had formed around the N to E sides of the vent, and the opposite side of the vent edge, and the slope above it, had collapsed. ", Lava carves channels in ice; bulge on opposite flank. Throughout August 2010, most of the 485 seismic events recorded were long period; the largest of which was an M 2.1 located on the E edge of the caldera. In February, only five seismic events were recorded with very little harmonic tremor. Historical eruptions at Chile's Villarrica, documented since 1558, have consisted largely of mild-to-moderate explosive activity with occasional lava effusion. Volcanoes at a Plate Boundary. The temperature of the lava lake was measured at a maximum of 1,000°C on 25 July. POVI reported that satellite images of Villarrica acquired on 25 July revealed a weak thermal anomaly. Seismicity and explosive activity in the crater both began decreasing on 12 September and continued a downward trend at least through 16 September. The 2840m-high Villarrica is an active volcano with a lava lake in its crater. Some gas explosions were observed to hurl volcanic bombs as far as ~300 m. Source: Villarrica Volcano Visual Surveillance Project. This eruption continues to this date, often with a lava lake at its summit which can generate small explosions, ash and volcanic bombs. At that date, the central pit was ~100 m deep, with two small degassing vents at the bottom. Volcanologists from POVI reported an increase in activity during February (figure 44), including a sudden collapse of about 10 m of much of the material in the lava pit on 9 February, after which a new rise began almost immediately (figure 45). Weak night glow over the summit after 21 days of absence, indicating infilling of the crater floor with incandescent lava. On 4 and 5 February 2015 POVI observed the first Strombolian eruptions inside of the summit crater vent since April 2012, and constant strong degassing occurring in 10 minute pulses. Two days later SERNAGEOMIN raised the alert level to Orange (3 of 4) based on increased DR values close to 80 cm2 and seismic amplitudes of 40 μm/s, as well as increased Strombolian activity and bombs ejected to 500-600 m from the crater. The number of monthly seismic events remained in the 10,000-12,000 range through 2014, while the other parameters measured by OVDAS remained stable. In the slope in front of the lava flow there were three dense columns of water vapor produced by the slow glacier fussion. Information Contacts: G. Fuentealba and P. Riffo, Univ de la Frontera. Two small ash emissions occurred on 7 March. Seismographs indicated harmonic tremor at base levels and at 1400 on 9 October, tremor bands were recorded. Sentinel-2 captured on average twelve images of Villarrica each month (figure 93). Information Contacts: Gustavo Fuentealba1 and Paola Peña S., Observatorio Volcanológico de Los Andes del Sur (OVDAS), Manantial 1710-Carmino del Alba, Temuco, Chile; 1Universidad de La Frontera (UFRO), Departamento Ciencias Fisicas, Universidad de la Frontera, Avda. Information Contacts: G. Fuentealba, M. Murillo, M. Petit-Breuilh, and P. Peña, SAVO, Univ de la Frontera, Fundación Andes; J. Cayupi, SERNAGEOMIN. An energetic long-period event on 15 September, the culmination of this period of high-amplitude tremor, is considered to have been associated with a small explosive event in the crater and ash emission. Information Contacts: G. Fuentealba C., P. Riffo A., and P. Acevedo, Univ. They also saw a dark gray stain trending N 120° E reaching at least 6 km (to the Portezuelo Chinay area). The next day (27 September) was partly cloud-covered, but strong fumarolic activity formed low-lying scrolls directed toward the E. Later, during a clearing in the clouds, observers saw a 500-m-long ash fall layer extending W. Several seismic stations were installed on 26 September. Villarrica volcano is located in the lakes district of Chile, about 650 km south of Santiago. The location of the tremor signal was also shallower than it had been previously. Many of the world's volcanoes are the result of subduction at a convergent plate boundary… The highest explosion of spatter reached 300 m above the crater, and material fell 500 m away onto the flanks. In January activity was at normal levels. Strombolian activity increased on 22 July with the highest intensity activity in four years continuing through the 25th (figure 81). Temperatures close to 800°C were measured that day near the lava lake surface on a flyover supported by ONEMI; tephra was observed around the crater rim and a thin layer of ash was distributed on the flanks. Incandescent material continued to be ejected from the crater, but with less frequency, and was deposited near the crater on the NE flank. Sentinel-2 satellite imagery showed bright thermal anomalies at the summit on 1, 3, 4, 6, 9, 11, 14, 16, 19, 26, 29, and 31 March, twelve of the fourteen days images were taken. Information Contacts: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Observatorio Volcanológico de Los Andes del Sur (OVDAS), Avda Sta María No. Height – 2847 m. Villarrica is a classical cone-shaped ‘stratovolcano’, that rises over 1500 m above the surrounding countryside up to the summit. Geotherm. The Buenos Aires VAAC (Volcanic Ash Advisory Center) reported a plume to 9.1 km altitude drifting ESE later in the day. An aerial view of the summit on 15 October showed a solid and fractured lava crust on the bottom of the crater and very low gas emission that was mainly water vapor caused by the melting and evaporation of small blocks of ice and snow that fell into the crater. This behavior continued until 1900 on 15 February. Res., 134: 303-337. 0104, Santiago, Chile (URL: http://www.sernageomin.cl/); Projecto Observación Visual Volcán Llaima (POVI) (URL: http://www.povi.cl/llaima/). POVI reported that sometime during mid-morning on 18 July webcam images captured two vapor-and-gas emissions with some ash rising from Villarrica. On 12 March, the volcano guides observed a light dusting of ash that covered the NE flank of the volcano. Figure 17 shows an ~4-year record of these estimates. Observations by local residents suggest that during the early morning of 26 September a second explosion occurred, depositing new ash. | October On 16 November, a small lava lake was visible in the crater from the air; it was photographed on the 19th (figure 18). After the eruption, observers continued to monitor Villarrica. SERNAGEOMIN reported that on 26 October three gray plumes with little ash content were emitted from Villarrica and rose to an altitude of 3.2 km (10,500 ft) a.s.l. Res., 190: 297-311. | June A constructive plate boundary Iceland Eyjafjallajökull © Flickr; Bjarki Sigursveinsson A destructive plate boundary Villarrica, Chile Mount Villarrica © Flickr; Gerben van Heijningen Mauna Loa and Kilauea Mauna Loa © Flickr; Aubrey Saunders Kilauea Volcano © Flickr; Greg Bishop Mount Etna Etna 12 may 2011 © Flickr; Helena Eriksson The structure of a composite volcano Edinburgh Castle Edinburgh … POVI reported that during an over-flight of Villarrica on 9 December scientists observed a small lava lake, 10-15 m in diameter, partially covered by floating black solidified lava. Detonations from the crater were heard during 10-12 December. Satellite-based MODIS thermal alerts were first detected at 0345 UTC on 5 November and also occurred on 6, 16, 17, 22, 24, and 29 November, 5, 8, 9, 14, 19, 21, and 31 December, and 1 and 2 January 2005. On 27 September incandescence from the lava lake were reflected in the cloud cover above. A subducting plate creates volcanoes. ONEMI maintained an Alert Level Yellow (the middle level on a three-color scale) for the municipalities of Villarrica, Pucón (16 km N), Curarrehue, and the commune of Panguipulli, and the exclusion zone for the public of 500 m around the crater. POVI observed the presence of particulate matter suspended over Villarrica on 9 December, and a light dusting of material within 1,000 m of the summit the following day. Lahars are one of the most prevalent and serious hazards at many volcanoes, as they can often be triggered (for example by snow-melt, or rain fall) without there being any significant eruption. Information Contacts: HIGP MODIS Thermal Alert System, Hawai'i Institute of Geophysics and Planetology (HIGP), University of Hawaii and Manoa, 168 East-West Road, Post 602, Honolulu, HI 96822, USA (URL: http://modis.higp.hawaii.edu/). A report on a 22 July visit stated that both incandescence and the level of the lava surface were low when compared to 19 June. On 13, 25, and 30 June, small phreatic emissions rose up to 200 m above the summit. SERNAGEOMIN raised the Alert Level from Green to Yellow in early August 2019 due to the increase in activity that included incandescent ejecta and bombs reaching 200 m from the summit crater (BGVN 44:09). Persistent minor gas-and-ash emissions, with small blocks and lapilli ejected onto the crater rim, were captured by the webcams and observed by visitors near the summit every month. ONEMI maintained an Alert Level Yellow (the middle level on a three-color scale) for the municipalities of Villarrica, Pucón (16 km N), Curarrehue, and the commune of Panguipulli, and changed the exclusion zone for the public to a radius of 1 km around the crater. Erta Ale Ethiopia Shield (mid plate) volcano. During that time, there were 118 thermal alerts derived from the Hawai'i Institute of Geophysics and Planetology Thermal Alerts System (MODVOLC). Strombolian explosions from a vent on the crater floor continued throughout the remainder of March.