Sabancaya

Photo of this volcano
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 15.787°S
  • 71.857°W

  • 5960 m
    19549 ft

  • 354006
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Weekly Report: 12 July-18 July 2017 Citation IconCite this Report


Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya increased compared to the previous week; there was an average of 19 explosions recorded per day during 10-16 July. Gas-and-ash plumes rose 3.5 km above the crater rim and drifted more than 40 km NW and E. Sulfur dioxide flux was as high as 2,959 tons per day, recorded on 16 July. The MIROVA system detected six thermal anomalies. An explosion at 0931 on 19 July generated an ash plume that rose 4 km above the crater rim and drifted N.

Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET), Instituto Geofísico del Perú (IGP)


Most Recent Bulletin Report: May 2017 (BGVN 42:05) Citation IconCite this Report


Eruption with continuing ash plumes began on 6 November 2016

Although historical records of eruptive activity at Peru's Sabancaya volcano go back to 1750, there have only been a handful documented since the 1980s; activity that began in 1986 was the first recorded in over 200 years. During the last period of substantial ash eruptions between 1990 and 1998 ashfall deposits up to 4 cm thick were reported 8 km E of the volcano. Evidence for minor ash-emitting events was reported in 2000 and 2003. Intermittent seismic unrest and fumarolic emissions characterized activity from late 2012 through 2015. Seismically detected explosions during August 2014 led to releases of SO2 gases and steam plumes, some as high as 2 km, along with possible minor volcanic ash. Possible minor volcanic ash emissions were also mentioned by Peruvian authorities and pilot reports between September and December2014 but there were no confirmed reports of ash emissions during this period. A crater inspection during 9-10 July 2015 found trace amounts of ash at the crater that contained crystals of plagioclase, biotite, and amphibole, along with fresh volcanic glass. These were interpreted by the volcanologists to represent minor ash emissions during recent weeks.

Unrest with steam plumes and variable seismicity continued during 2016 until 6 November when continuous ash-bearing explosions began. Activity during 2016 through February 2017 is covered in this report with information from the two Peruvian observatories that monitor the volcano: Instituto Geofisico del Peru - Observatoria Vulcanologico del Sur (IGP-OVS), and Observatorio Volcanologico del INGEMMET (Instituto Geológical Minero y Metalúrgico) (OVI-INGEMMET). Aviation reports and notices come from the Buenos Aires Volcanic Ash Advisory Center (VAAC), and satellite data is reported from several sources.

Sabancaya maintained a level of seismic and fumarolic unrest through most of 2016, similar to levels recorded in 2014 and 2015, with almost constant water-vapor and SO2 plumes rising from the crater. Additionally, tectonic (not volcanic) seismicity caused damage and fatalities in nearby villages. An explosion on 27 August 2016 did not produce ash, but new areas of fumarolic activity on the N flank were observed around this time. Hybrid seismic events related to the movement of magma, and SO2 emissions, increased noticeably during September and October 2016. An explosive eruption with numerous ash plumes began on 6 November 2016. Continuous ash emissions with plume heights exceeding 10 km altitude were recorded several times through February 2017. Thermal anomalies were first measured in satellite data in early November, along with numerous significant SO2 plumes.

Activity during January-October 2016. Heights of plumes consisting of water vapor and minor magmatic gases generally decreased during January 2016, from 1,800 m to less than 1,200 m by the month's end. Seismic activity was generally low in terms of both numbers of events and magnitude. The daily number of events ranged from 8 to 20, and the largest event, a M 4.0, was registered on 29 January.

Plume heights continued declining in February, from 1,000 m during the first week to 400-800 m by the end of the month. During March, April, and May the heights of steam and SO2 plumes ranged from 200 to 1,300 m above the crater, and values of SO2 flux ranged from 600 to 1,500 metric tons per day (t/d). These values increased only slightly in July and August; plumes rose 2,000 m above the crater rim and SO2 emissions were as high as 2,600 t/d.

Seismicity continued at low levels through late August. Three significant tectonic earthquakes in mid-August were not related to volcanic activity, but the earthquake 25 km NE of Sabancaya on the Ichupampa fault on 14 August caused at least four fatalities, and numerous aftershocks were recorded in the region. A spike in SO2 emissions at the volcano to 4,030 t/d occurred shortly after the earthquake.

On 27 August 2016 there was a hybrid-type seismic event that IGP-OVS interpreted as an explosion of 72 MJ (Megajoules) of energy. An official statement from the Scientific and Technical Committee for Risk Management (IGP-OVS, OVI-INGEMMET, and others) issued on 6 September noted that "dense gray gases reached 1,000 m above the crater and drifted E." However, no VAAC reports were issued, and ash was not mentioned in the OVI INGEMMET weekly report.

During the last two weeks of August, two large zones of new fumarolic activity were detected in satellite imagery. OVI visited the site on 25 August, and IGP-OVS visited on 1 September 2016. The scientists observed areas of increased fumarolic emissions outside of the crater on the NE and NW flanks of the volcano (figure 19). The first zone was located on the NW flank and extended from the vicinity of the crater down to 5,700 m elevation, while the second area was located on the NE flank at about 5,600 m. Both areas follow a NW-SE trend. The flux of SO2 increased to values greater than 4,000 t/d at the end of August.

Figure (see Caption) Figure 19. New areas of fumarolic activity at Sabancaya, August 2016. Top: Two large fumarolic areas photographed on 1 September 2016 that appeared on the flanks during late August. The main zone was located on the NW flank and extended from the vicinity of the crater down to 5,700 m elevation, while the second area was located on the NE flank at about 5,600 m. Courtesy of IGP-OVS (Sabancaya Report 27, 1 September 2016) Bottom: Google Earth image showing location of fumarolic fields. A, B, C, and D are part of the NW flank field and E is the NE flank field. Courtesy of OVI-INGEMMET (Special Report, 1 September 2016).

OVI-INGEMMET reported an increase in the total number of seismic events during September 2016, especially hybrid-type events, along with generally lower plume heights, but increased emissions of SO2. IGP-OVS noted a swarm of hybrid-type seismic events on 27 September distinct from the distal tectonic-related events of the previous month, and indicative of an increase in volcanic activity. IGP-OVS returned to Sabancaya on 28 September 2016 to gather temperature measurements at the new fumarole areas. A NW-SE trending belt on the NE side of the volcano had temperature readings between 71° and 91°C.

At the beginning of October, water vapor and SO2 gas plumes rose as high as 2,000 m above the crater, and the SO2 flux was over 3,000 t/d. Volcanic seismicity increased from 220 earthquakes per day during the first week to 470 during the second week. SO2 emissions continued to increase and by 22 October were at 7,173 t/d.

From 9 January through 3 November 2016 the Buenos Aires VAAC issued 52 reports with pilot observations of ash. The VAAC was unable to confirm the presence of ash in emissions and instead described only water vapor or magmatic gases recorded via the web camera. There were no MODIS thermal anomalies shown by the MODVOLC or MIROVA systems from January 2014 through October 2016.

Activity during November 2016-February 2017. OVI-INGEMMET reported an eruption beginning at 2040 local time on 6 November 2016 (0140 on 7 November UTC) that started with an explosion and was followed by the continuous emission of low volume ash that rose up to 1,500 m above the crater rim (about 7,500 m altitude) (figure 20).

Figure (see Caption) Figure 20. The beginning of the eruption at Sabancaya, in the province of Caylloma in Arequipa, on 6 November 2016. Courtesy OVI-INGEMMET (Sabancaya 2016 Weekly Report 45).

Several types of volcanic-related seismic events continued to increase in number and intensity during November and December. The eruption exhibited an average of 39 daily explosive events with ash plumes (figures 21, 22, and 23) between 7 November and 15 December. There were 63 explosions on 30 November, and between 5 and 11 December there were 328 explosions.

Figure (see Caption) Figure 21. Ash plume rising over 4,000 m above the summit (5, 967 m elevation) at Sabancaya, 24 November 2016. Courtesy OVI-OVS (2016 Sabancaya Joint OVI-OVS Weekly Report 2, 21-27 November).
Figure (see Caption) Figure 22. Plume heights and compositions at Sabancaya from 28 October through 27 November 2016. Ash emissions began on 6 November, and continued to increase in density and plume height throughout the month. White circles represent water vapor, light gray are ash, dark gray are abundant ash, blue are SO2 gas, and yellow are sulfur aerosols. Courtesy OVI-OVS (2016 Sabancaya Joint OVI-OVS Weekly Report 2, 21-27 November).
Figure (see Caption) Figure 23. NASA Earth Observatory images of ash plumes from Sabancaya on 16 and 19 November 2016. The bright area to the SW in the 16 November image is snow near the peak of Mount Ampato, which is covered with ash in the 19 November image. The 16 November image was acquired by a multispectral imager on the European Space Agency's Sentinel 2 spacecraft. The Operational Land Imager (OLI) on Landsat 8 captured the November 19 image. Courtesy of NASA Earth Observatory.

Ash emissions were continuous from the beginning of the eruption through mid-December, with heights up to 4.5 km (10.5 km altitude) above the crater, according to the Scientific-Technical Committee of government scientists monitoring the eruption. Ashfall several millimeters thick was recorded in areas as far as 40 km away. During the first weeks of the eruption ash fell mainly to the E and NE on the villages of Maca, Achoma, Yanque and Chivay (18-30 km NE). Later in December, ashfall was reported W and NW in the villages of Huambo (28 km W), Cabanaconde (22 km NW), and Pinchollo (18 km N). On 26 December, ashfall was again reported in the villages of Cabanaconde, Pinchollo, and Tapay (25 km NW) to the NW and N, and Lari and Madrigal (20 km NE), Maca, and areas of Achoma to the NE. The seismic energy released from tremors and explosive events continued to increase throughout November into December (figures 24 and 25).

Figure (see Caption) Figure 24. Seismic energy and types of seismic events at Sabancaya, 6 November-8 December 2016. HIB are hybrid-type seismic events, TRE are tremors, EXP are explosions. Black line represents cumulative energy in Megajoules (MJ). Y axis is daily seismic energy on the left and cumulative energy on the right. Stars represent the period of continuous explosions. Courtesy of OVI-OVS (2016 Sabancaya Joint OVI-OVS Weekly Report 4, 5-11 December).
Figure (see Caption) Figure 25. Web camera image of ash-and-steam plume at Sabancaya, 9 December 2016. Courtesy of OVI-OVS (2016 Sabancaya Joint OVI-OVS Weekly Report 4, 5-11 December).

Beginning on 21 December there was a notable increase in seismicity (mainly of hybrid events), in the number (up to 52 per day) and height of plumes, and ash emissions. These changes led the Scientific-Technical Committee to raise the Volcanic Warning Level from Yellow to Orange (2 to 3 on a 4-level scale) on 28 December, warning people to remain more than 12 km from the crater (figures 26 and 27). A small lahar affected the area of Pinchollo (18 km N) on 3 January 2017.

Figure (see Caption) Figure 26. Dense ash cloud at Sabancaya, 26 December 2016. Increasing intensity of seismicity and number of explosions led to an increase in the Volcano Warning Level on 28 December. Courtesy of OVI-OVS (Informe Especial No. 01-2017).
Figure (see Caption) Figure 27. Seismic energy released by Sabancaya between 5 December 2016 and 4 January 2017. Note increasing energy of the explosions in early January. Courtesy of OVI-OVS (Informe Especial No. 01-2017).

Seismicity remained high during January with long-period (LP), tremor, and hybrid-type events all continuing, and an average of 70-76 daily explosions. During the second week in January explosions peaked at an average of 84 per day. This number decreased during early February to around 20 per day but then rose back to over 40 by the end of the month. A significant number of hybrid seismic events occurred during the last week of February.

Gas-and-ash plumes rose to 4.5 km above the crater in early January, dropping back to 2-3 km for the rest of the month, before rising again to 3-4 km (9-10 km altitude) during February. In their Special Report in January 2017, the joint Scientific-Technical committee presented a map showing that ash dispersal had affected communities in nearly every direction 40 km from the summit (figure 28).

Figure (see Caption) Figure 28. Area affected by ashfall (in pink) from Sabancaya as of mid-January 2017. Courtesy of OVI-OVS (Informe Especial No. 01-2017).

Buenos Aires VAAC Reports, November 2016-February 2017. The Buenos Aires VAAC first noted minor amounts of volcanic ash in emissions visible from the volcano webcam on 7 November 2016 (UTC). Ash was not identified in satellite imagery until midday 8 November when it was reported at 7.6 km altitude (about 1.7 km above the summit). Observations of continuous emissions of steam and ash were reported daily, when not obscured by weather, from then through the end of February 2017. Plume heights were commonly 7.6-8.2 km altitude, about 1.7-2.3 km above the summit. Higher plumes were also recorded a number of times during this period, including 10.3 km altitude on 17 and 23 November. The plume was clearly visible in satellite imagery on 24 November, drifting SE at 10.9 km. Plumes on 3 December rose 10 km and drifted SW; they were partially hidden by weather clouds. Pulses of volcanic ash drifting over 35 km SE at 10.6 km altitude were visible on 11 and 12 December. For most of January 2017 the plumes were obscured by weather clouds, but were visible on 6 January at 9.1 km altitude. Higher plumes were more often recorded in February; they rose continuously over 10 km from 4 to 7 February. The highest plume during the period was on 26 February, at 11.9 km, drifting SW.

Thermal anomalies in satellite data. The MIROVA thermal anomaly plot of MODIS data provided independent satellite confirmation of the beginning of the eruption. The first thermal anomaly appeared on 2 November 2016, and values increased in frequency and intensity in the subsequent weeks. Energy values reached moderate levels in early February 2017 (figure 29). The first MODVOLC thermal alert pixel for Sabancaya appeared on 6 January 2017. There were seven MODVOLC alert pixels in January and six in February, suggesting a persistent source of heat during this time.

Figure (see Caption) Figure 29. Log Radiative Power values for Sabancaya between 13 March 2016 and 13 March 2017. The first MIROVA-identified thermal anomaly was on 2 November 2016, and values increased in frequency and intensity after that. Courtesy of MIROVA.

Sulfur dioxide data. Sulfur dioxide plumes from Sabancaya were captured numerous times by the OMI satellite instrument from NASA's Global Sulfur Dioxide Monitoring system between November 2016 and February 2017. They revealed significant SO2 plumes travelling in all directions away from the summit for distances up to 200 km (figure 30).

Figure (see Caption) Figure 30. SO2 plumes drifting in different directions up to 200 km from Sabancaya captured by the OMI instrument on the Aura satellite. Clockwise from top left: 7 November 2016, first day of ash eruption, plume drifting SW and S towards Arequipa; 16 November 2016, plume drifting NE toward Lake Titicaca; 25 December 2016, plume drifting WSW over the Pacific Ocean; 27 February 2017, large plume drifting S and W, corresponding to an 11.9-km-altitude ash plume reported by Buenos Aires VAAC on 26 February. Courtesy of NASA GSFC.

Information Contacts: Observatorio Volcanologico del INGEMMET, (Instituto Geológical Minero y Metalúrgico), Barrio Magisterial Nro. 2 B-16 Umacollo - Yanahuara Arequipa, (URL: http://ovi.ingemmet.gob.pe); Instituto Geofisico del Peru, Observatoria Vulcanologico del Sur (IGP-OVS), Arequipa Regional Office, Urb La Marina B-19, Cayma, Arequipa, Peru (URL: http://ovs.igp.gob.pe/); NASA Earth Observatory, EOS Project Science Office, NASA Goddard Space Flight Center, Goddard, Maryland, USA (URL: http://earthobservatory.nasa.gov/); 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/); Hawai'i Institute of Geophysics and Planetology (HIGP), MODVOLC Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://modis.higp.hawaii.edu/); NASA Goddard Space Flight Center (NASA/GSFC), Global Sulfur Dioxide Monitoring Page, Atmospheric Chemistry and Dynamics Laboratory, Goddard, Maryland, USA (URL: http://so2.gsfc.nasa.gov/index.html ).

Weekly Reports - Index


2017: January | February | March | April | May | June | July
2016: September | November | December
2015: July | August | December
2014: July | August | September | October | December
2013: February | March | April | May


12 July-18 July 2017 Citation IconCite this Report


Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya increased compared to the previous week; there was an average of 19 explosions recorded per day during 10-16 July. Gas-and-ash plumes rose 3.5 km above the crater rim and drifted more than 40 km NW and E. Sulfur dioxide flux was as high as 2,959 tons per day, recorded on 16 July. The MIROVA system detected six thermal anomalies. An explosion at 0931 on 19 July generated an ash plume that rose 4 km above the crater rim and drifted N.

Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


5 July-11 July 2017 Citation IconCite this Report


Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya increased compared to the previous week; there was an average of 10 explosions recorded per day during 3-9 July, and the explosions were more energetic. Gas-and-ash plumes rose 5.5 km above the crater rim and drifted more than 50 km NW and S. Sulfur dioxide flux was as high as 2,239 tons per day.

Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


28 June-4 July 2017 Citation IconCite this Report


Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya continued to decline; there was an average of five explosions recorded per day during 26 June-2 July. The explosions were also less energetic. Gas-and-ash plumes rose as high as 1.5 km above the crater rim and drifted more than 30 km SE. Sulfur dioxide flux was as high as 1,472 tons per day, recorded on 1 July.

Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


21 June-27 June 2017 Citation IconCite this Report


Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya decreased from the previous week; there was an average of 15 explosions recorded per day during 19-25 June. The explosions were also less energetic. Gas-and-ash plumes rose as high as 3.5 km above the crater rim and drifted more than 40 km S. The MIROVA system detected as many as 10 thermal anomalies, spread over the SE, N, and NE flanks. Sulfur dioxide flux was as high as 5,700 tons per day, recorded on 24 June.

Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


14 June-20 June 2017 Citation IconCite this Report


Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya slightly decreased from the previous week; there was an average of 26 explosions recorded per day during 12-18 June. Gas-and-ash plumes rose as high as 3.7 km above the crater rim and drifted more than 40 km SW. The MIROVA system detected nine thermal anomalies, spread over the SE, N, and NW flanks. Sulfur dioxide flux was as high as 3,557 tons per day on 14 June.

Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


7 June-13 June 2017 Citation IconCite this Report


Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya slightly decreased from the previous week; there was an average of 31 explosions recorded per day during 5-11 June. The number and magnitude of long-period and hybrid events were moderate and low, respectively. Levels of long-period events were moderate and hybrid events were low. Gas-and-ash plumes rose as high as 2.8 km above the crater rim and drifted more than 30 km E and SE. The MIROVA system detected four thermal anomalies, spread over the SE, N, and NW flanks. Sulfur dioxide flux was as high as 3,392 tons per day on 6 June.

Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


31 May-6 June 2017 Citation IconCite this Report


Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that for the second week in a row explosive activity at Sabancaya slightly increased from the previous week; there was an average of 47 explosions recorded per day during 29 May-4 June. Seismicity was dominated by long-period events, and the number and magnitude of hybrid events were low. Gas-and-ash plumes rose as high as 3 km above the crater rim and drifted more than 40 km E and SE. The MIROVA system detected five thermal anomalies, spread over the SE, N, and NW flanks. Sulfur dioxide flux was as high as 1,703 tons per day on 3 June.

Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


24 May-30 May 2017 Citation IconCite this Report


Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that during 22-28 May explosive activity at Sabancaya slightly increased from the previous week, with an average of 41 explosions detected per day. Seismcity was dominated by long-period events, and the number and magnitude of hybrid events were low. Gas-and-ash plumes rose as high as 2.8 km above the crater rim and drifted more than 30 km E and SE. The MIROVA system detected two thermal anomalies.

Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


17 May-23 May 2017 Citation IconCite this Report


Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that during 15-21 May explosive activity at Sabancaya was similar to the previous week, with an average of 39 explosions detected per day. The number and magnitude of long-period and hybrid events was low. Gas-and-ash plumes rose as high as 4.2 km above the crater rim and drifted more than 40 km NE, E, and SE. The MIROVA system detected six thermal anomalies.

Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


10 May-16 May 2017 Citation IconCite this Report


Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that during 8-14 May explosive activity at Sabancaya slightly decreased from the previous week, with an average of 38 explosions detected per day. The number of long-period events continued to increase, while hybrid events were sporadic. Gas-and-ash plumes rose as high as 4.2 km above the crater rim and drifted more than 40 km NE, E, and SE.

Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


3 May-9 May 2017 Citation IconCite this Report


Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that during 1-7 May explosive activity at Sabancaya increased, with an average of 41 explosions detected per day. The number of long-period and hybrid events also increased. Ash plumes rose as high as 3.5 km above the crater rim and drifted more than 40 km NE and E.

Based on webcam images, satellite views, and seismic data the Buenos Aires VAAC reported that during 3-9 May sporadic gas-and-ash puffs rose to altitudes of 7-8.2 km (23,000-27,000 ft) a.s.l. and drifted SE, E, and NE.

Sources: Buenos Aires Volcanic Ash Advisory Center (VAAC); Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


26 April-2 May 2017 Citation IconCite this Report


Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that during 24-30 April seismicity at Sabancaya slightly declined compared to the previous week, with an average of 33 explosions recorded per day. Ash plumes rose as high as 3.2 km above the crater rim and drifted more than 40 km SE. Based on webcam images, satellite views, and seismic data the Buenos Aires VAAC reported sporadic gas-and-ash puffs during 25 April-2 May. Strong ash plumes rose to an altitude of 7.9 km (26,000 ft) a.s.l. (or 2.4 km above the crater rim) and drifted SE on 26 and 28 April.

Sources: Buenos Aires Volcanic Ash Advisory Center (VAAC); Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


19 April-25 April 2017 Citation IconCite this Report


Based on webcam images, satellite views, and seismic data the Buenos Aires VAAC reported sporadic gas-and-ash puffs from Sabancaya during 18-25 April, sometimes rising as high as 8.2 km (25,000 ft) a.s.l.; clouds sometimes hindered observations of the volcano.

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)


12 April-18 April 2017 Citation IconCite this Report


Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that during 10-16 April seismicity at Sabancaya increased compared to the previous week, with an average of 37 explosions recorded per day. Ash plumes rose as high as 3 km above the crater rim (13 April) and drifted more than 40 km NW and SE. The Buenos Aires VAAC reported that on 17 April ash plumes rose to an altitude of 7.9 km (26,000 ft) a.s.l. and drifted SE. The next day ash emissions were recorded by the webcam. The Alert Level remained at Orange (the second highest level on a four-color scale).

Sources: Buenos Aires Volcanic Ash Advisory Center (VAAC); Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


5 April-11 April 2017 Citation IconCite this Report


Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that during 3-9 April seismicity at Sabancaya declined compared to the previous week, with an average of 27 explosions recorded per day. Ash plumes rose as high as 3.2 km above the crater rim (on 8 April) and drifted more than 40 km NW and NE. Ashfall was reported in Pinchollo (20 km N), Maca, and Chivay. The Buenos Aires VAAC reported that diffuse ash plumes drifted 100 km E on 9 April. Intermittent ash emissions during 10-11 April rose as high as 7 km (23,000 ft) a.s.l. and drifted SE. The Alert Level remained at Orange (the second highest level on a four-color scale).

Sources: Buenos Aires Volcanic Ash Advisory Center (VAAC); Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


29 March-4 April 2017 Citation IconCite this Report


Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that during 27 March-2 April there were an average of 41 explosions recorded per day. The number and magnitude of hybrid events decreased while long-period events increased. Ash plumes rose as high as 4.8 km above the crater rim and drifted more than 40 km NW, N, and SW. Ashfall was reported in Pinchollo (20 km N) and Cabanaconde (22 km NW). Overall activity increased compared to the precious week. The Alert Level remained at Orange (the second highest level on a four-color scale).

Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


22 March-28 March 2017 Citation IconCite this Report


Based on webcam images, satellite views, and seismic data the Buenos Aires VAAC reported sporadic gas-and-ash puffs from Sabancaya during 24-27 March, sometimes rising as high as 9.1 km (30,000 ft) a.s.l. Weather clouds often hindered observations of the volcano, especially during 22-3 and 25 March.

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)


15 March-21 March 2017 Citation IconCite this Report


Based on webcam images, satellite views, and seismic data the Buenos Aires VAAC reported sporadic gas-and-ash puffs from Sabancaya during 14-15, 17-19, and 21 March, sometimes rising as high as 8.2 km (27,000 ft) a.s.l. Weather clouds often hindered observations of the volcano. Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that at 0802 on 21 March an ash plume rose 2 km and drifted more than 30 km SSE.

Sources: Buenos Aires Volcanic Ash Advisory Center (VAAC); Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


8 March-14 March 2017 Citation IconCite this Report


Based on webcam images, satellite views, and seismic data the Buenos Aires VAAC reported that during 8-14 March sporadic gas-and-ash puffs rose from Sabancaya. Weather clouds often hindered observations of the volcano. On 9 March ash plumes rose to an altitude of 11 km (36,000 ft) a.s.l. and drifted NW and SW. Ash plumes rose to an altitude of 6.7 km (22,000 ft) a.s.l. on 12 March.

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)


1 March-7 March 2017 Citation IconCite this Report


Based on webcam images, satellite views, and seismic data the Buenos Aires VAAC reported that during 1-4 and 6-7 March sporadic gas-and-ash puffs rose from Sabancaya. Weather clouds often hindered observations of the volcano. On 3 March ash plumes rose to altitudes of 9.1-10.4 km (30,000-34,000 ft) a.s.l. and drifted W, SW, and S. Intermittent increases in seismicity were also detected that day.

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)


22 February-28 February 2017 Citation IconCite this Report


Based on webcam views and seismic data the Buenos Aires VAAC reported that during 22-26 and 28 February sporadic gas-and-ash puffs rose from Sabancaya, and during 24-28 February they rose to altitudes of 7-11.9 km (23,000-39,000 ft) a.s.l. Weather clouds often hindered observations of the volcano.

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)


15 February-21 February 2017 Citation IconCite this Report


Based on webcam views, satellite images, and seismic data the Buenos Aires VAAC reported that during 14-21 February sporadic gas-and-ash puffs rose from Sabancaya, and during 16-17 and 20 February rose to altitudes of 7.3-8.2 km (24,000-27,000 ft) a.s.l. Weather clouds often hindered observations of the volcano.

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)


8 February-14 February 2017 Citation IconCite this Report


Based on webcam views, satellite images, and seismic data the Buenos Aires VAAC reported that during 8-10 and 12-14 February sporadic gas-and-ash puffs rose from Sabancaya as high as an altitude of 9.1 km (30,000 ft) a.s.l.

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)


1 February-7 February 2017 Citation IconCite this Report


Based on webcam and satellite views, the Buenos Aires VAAC reported that sporadic gas-and-ash puffs rose from Sabancaya during 2-6 February. Weather clouds sometimes prevented visual observations.

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)


25 January-31 January 2017 Citation IconCite this Report


Based on webcam and satellite views, and seismic data, the Buenos Aires VAAC reported that sporadic gas-and-ash puffs rose from Sabancaya during 25-31 January. Weather clouds sometimes prevented visual observations. A field team from IGP's Observatorio Vulcanológico del Sur (OVS) visited Sabancaya on 26 January and observed ash plumes from explosions rising about 2 km above the crater rim.

Sources: Buenos Aires Volcanic Ash Advisory Center (VAAC); Instituto Geofísico del Perú (IGP)


18 January-24 January 2017 Citation IconCite this Report


Based on webcam and satellite views, the Buenos Aires VAAC reported that sporadic gas-and-ash puffs rose from Sabancaya during 17-24 January. Meteorological cloud cover sometimes prevented observations.

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)


11 January-17 January 2017 Citation IconCite this Report


Based mostly on webcam views, the Buenos Aires VAAC reported that sporadic gas-and-ash puffs rose from Sabancaya during 11-14 and 16-17 January. Partial satellite views on 13 January revealed an ash plume at an altitude of 7.6 km (25,000 ft) a.s.l. On 16 January a pilot observed an ash plume that had risen to an altitude of 8.2 km (25,000 ft) a.s.l., though meteorological cloud cover prevented satellite and webcam confirmation.

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)


4 January-10 January 2017 Citation IconCite this Report


Based on webcam and satellite views, the Buenos Aires VAAC reported that during 3-10 January intermittent ash puffs from Sabancaya likely rose as high as 9.1 km (30,000 ft) a.s.l. and drifted WSW, W, N, and NE; weather clouds sometimes obscured satellite and webcam views, and the webcam was not operational during 5-6 January.

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)


28 December-3 January 2017 Citation IconCite this Report


On 28 December the Technical and Scientific Committee for volcanic risk management of the Arequipa region (comprised of five groups including IGP's OVS and INGEMMET's OVI) recommended that the Alert Level for Sabancaya be raised from Yellow to Orange based on increased activity detected during 8 November-26 December. A progressive increase in the number of explosions per day to 52 was noted along with the detection of 14 daily hybrid events. Harmonic tremor was recorded on 21, 24, and 25 December. Thermal anomalies were identified by the MIROVA system with the last one being recorded on 24 December. Gas-and-ash plumes rose as high as 4.5 km above the crater and drifted 40 km in different directions, affecting the villages of Maca, Achoma, Yanque, and Chivay, and areas to the W and NW including Huambo, Cabanaconde, Pinchollo, Lari, Tapay, and Madrigal. The public was warned to stay at least 12 km away from the volcano. An explosion on 2 January 2017 generated an ash plume that rose 2.5 km and drifted more than 30 km S and SW.

Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


21 December-27 December 2016 Citation IconCite this Report


Based on webcam and satellite views, the Buenos Aires VAAC reported that during 21-26 December intermittent, strong ash puffs from Sabancaya rose 6.4-7.6 km (25,000-28,000 ft) a.s.l. and drifted in multiple directions.

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)


14 December-20 December 2016 Citation IconCite this Report


IGP's OVS reported that during 12-18 December seismicity at Sabancaya continued to be dominated by long-period earthquakes; hybrid earthquakes decreased from 14 events per day to 6. Gas-and-ash plumes rose as high as 3.5 km above the crater and drifted more than 35 km NW, E, SE, and S.

Based on webcam and satellite views, the Buenos Aires VAAC reported that during 14-20 December gas-and-water-vapor emissions and sporadic ash puffs rose 6.4-8.2 km (21,000-27,000 ft) a.s.l. (2.3 km above the crater) and drifted SW, WSW, W, and NW.

Sources: Buenos Aires Volcanic Ash Advisory Center (VAAC); Instituto Geofísico del Perú (IGP)


7 December-13 December 2016 Citation IconCite this Report


Although weather clouds often prevented webcam and satellite views of Sabancaya, the Buenos Aires VAAC noted that some clear observations during 7-13 December revealed continuous gas-and-water-vapor emissions with sporadic ash puffs which rose to variable heights. Plumes drifted SW, SE, and ENE.

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)


30 November-6 December 2016 Citation IconCite this Report


The Technical and Scientific Committee for volcanic risk management of the Arequipa region (comprised of five groups including IGP's OVS and INGEMMET's OVI) reported that during 30 November-2 December and 5-6 December explosions at Sabancaya generated ash-and-gas plumes that rose as high as 4.5 km above the crater rim and drifted around 40 km in multiple directions. Inflation at the SE flank continued to be detected. Seismic activity remained constant; tremor amplitude greatly increased on 2 December.

Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


23 November-29 November 2016 Citation IconCite this Report


The Technical and Scientific Committee for volcanic risk management of the Arequipa region (comprised of five groups including IGP's OVS and INGEMMET's OVI) reported 288 explosions at Sabancaya during 21-27 November. Ash plumes rose as high as 4.5 km above the crater rim and drifted 35-40 km E and SE. Sulfur dioxide emissions were as high as 3,300 tonnes/day and deformation was detected on the SE flank. During 28-29 November ash plumes rose 2 km and drifted 30 km S and SE. The Alert level remained at Yellow; the public was warned to stay at least 10 km away from the volcano.

Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


16 November-22 November 2016 Citation IconCite this Report


The Technical and Scientific Committee for volcanic risk management of the Arequipa region (comprised of five groups including IGP's OVS and INGEMMET's OVI) reported multiple explosions at Sabancaya during 16-18 and 20-21 November, and ash plumes that rose 2-4.2 km above the crater rim and drifted more than 40 km N, NE, S, and SW. The Buenos Aires VAAC stated that ash plumes visible in satellite and webcam images drifted SE on 19 November.

Sources: Instituto Geofísico del Perú (IGP); Observatorio Vulcanológico del INGEMMET (OVI)


9 November-15 November 2016 Citation IconCite this Report


A Technical and Scientific Committee for volcanic risk management of the Arequipa region is comprised of five groups including IGP's Observatorio Vulcanológico del Sur (OVS) and INGEMMET's Observatorio Vulcanológico (OVI) and have been monitoring Sabancaya since 2013. The committee reported that new ash-bearing explosions began on 6 November. The explosions, detected at 2126, 2127, and 2149, produced ash plumes that rose 1.5 km above the crater rim and drifted E.

The frequency of hybrid earthquakes increased noticeably in early October and in the hours prior to the 6 November explosions. Volcanic gas emissions had also increased significantly, with values as high as 7,173 tons/day on 23 October. The MIROVA system had detected a thermal anomaly at the volcano on 2 November.

During 6-13 November ash-and-gas emissions from explosions and from periods in between explosions rose as high as 3 km above the crater. An event at 1320 on 8 November generated a significant ash plume that rose 2.4 km above the crater rim with ash dispersing within a 5-km radius. During 9-10 November ash plumes rose as high as 2 km and drifted 30-35 km SE, E, and NE, producing ashfall in the villages of Valle del Colca to the NE. On 11 November an explosion generated an ash plume that rose 3 km and drifted 40 km E and NE. An ash plume from an explosion the next day rose 2 km and drifted 30 km NE.

Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


2 November-8 November 2016 Citation IconCite this Report


Based on webcam and satellite views and notices from IGP, the Buenos Aires VAAC reported that during 7-8 November gas-and-water-vapor plumes with minor amounts of ash rose from Sabancaya to a maximum height of 2.2 km above the summit.

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)


7 September-13 September 2016 Citation IconCite this Report


Observatorio Vulcanológico del INGEMMET (OVI) reported that during a field inspection of Sabancaya on 25 August scientists noted five new fumarolic areas; two were located in the N part of the summit area, and three were on the NE flank. The number of hybrid earthquakes increased during 25-27 August. A small explosion at 0651 on 27 August produced a dense ash plume that rose 1 km above the crater and drifted E.

Source: Observatorio Vulcanológico del INGEMMET (OVI)


9 December-15 December 2015 Citation IconCite this Report


Instituto Geofísico del Perú (IGP) Observatorio Volcanológico del Sur (OVS) reported that during 9-14 December the number of volcano-tectonic (VT) earthquakes less than 6 km from the crater sharply increased; VT earthquakes in general were focused within 8 km of the crater at depths ranging from 3 to 15 km. White fumarolic plumes were steadily emitted, while bluish gasses were more sporadically observed. Gas plumes rose 800-1,400 m above the crater’s base. The Buenos Aires VAAC reported that during 11-12 December Sabancaya's webcam recorded weak emissions with minor amounts of ash.

Sources: Buenos Aires Volcanic Ash Advisory Center (VAAC); Instituto Geofísico del Perú (IGP)


26 August-1 September 2015 Citation IconCite this Report


The Buenos Aires VAAC reported that on 26 August a pilot observed an ash plume from Sabancaya rising to an altitude of 6.1 km (20,000 ft) a.s.l. and drifting E. Satellite images and the webcam showed gas-and-water-vapor plumes with possible diffuse ash coincident with a temporary and small increase in seismicity.

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)


15 July-21 July 2015 Citation IconCite this Report


INGEMMET volcanologists who climbed to the summit of Sabancaya during 9-10 July observed ash deposits from emissions during the previous weeks.

Source: Instituto Geológico Minero y Metalúrgico (INGEMMET)


24 December-30 December 2014 Citation IconCite this Report


Based on reports from INGEMMET, the webcam, and satellite images, the Buenos Aires VAAC reported that on 27 December water vapor and gas plumes from Sabancaya possibly contained small amounts of ash.

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)


22 October-28 October 2014 Citation IconCite this Report


IGP reported that during 21-27 October seismic activity at Sababcaya was low, and sporadic white and blue plumes rose as high as 1.2 km. Although a pilot reported an ash plume drifting E on 23 October, the Buenos Aires VAAC reported that ash was not detected in satellite images. The webcam showed gas-and-steam emissions, likely with diffuse ash, dissipating near the summit. On 25 October a pilot reported ash drifting E, but again satellite images did not detected ash.

Sources: Buenos Aires Volcanic Ash Advisory Center (VAAC); Instituto Geofísico del Perú (IGP)


24 September-30 September 2014 Citation IconCite this Report


IGP and INGEMMET reported that during 24-30 September seismicity at Sabancaya remained elevated; long-period, volcano-tectonic, and hybrid earthquakes were detected. White gas emissions rose as high as 1 km above the crater and drifted SE. The plumes were grayish from ash on 26 and 29 September.

Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


27 August-2 September 2014 Citation IconCite this Report


IGP reported that on 27 August INGEMMET reported long-period, volcano-tectonic, and hybrid earthquakes at Sabancaya. White to light gray plumes rose 100-300 m above the summit and drifted SE. On 28-29 August the Buenos Aires VAAC reported volcanic ash.

Sources: Buenos Aires Volcanic Ash Advisory Center (VAAC); Instituto Geológico Minero y Metalúrgico (INGEMMET)


20 August-26 August 2014 Citation IconCite this Report


IGP reported that on 24-25 August an increase in volcano-tectonic and long-period earthquakes, and during 23-25 August there was a slight increase in white to blueish white fumarolic emissions that rose 500-1500 m above the summit of Sabancaya. On 25 August during the night instruments detected a sequence of explosive events that lasted 82 seconds. On 26 August INGEMMET reported long-period, volcano-tectonic, and hybrid earthquakes. White to light gray plumes rose 100-1300 m above the summit drifting SE.

Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


13 August-19 August 2014 Citation IconCite this Report


On 13, 17, and 18 August the Buenos Aires VAAC reported volcanic ash at Sabancaya based on satellite, remote camera, and pilot reports.

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)


6 August-12 August 2014 Citation IconCite this Report


IGP reported that on 6 August there was increasing seismic and fumarolic activity at Sabancaya over the past four days. Fumarolic emissions increased, were white to blueish white and gray and rose to 3 km above the crater. On 9 August IGP reported an explosion that lasted 50 seconds at Sabancaya accompanied by increasing seismic activity including a strong increase in hybrid earthquakes. Intermittent views in cloudy conditions showed strong fumarolic emissions continued.

Source: Instituto Geofísico del Perú (IGP)


9 July-15 July 2014 Citation IconCite this Report


IGP reported that during 12-27 June there were renewed signs of activity from Sabancaya. Fumarolic activity increased and gases were notably more blue and gray. Seismicity also increased, particularly long-period (LP) earthquakes (~100 LP events per day during 18, 19, and 21 June). Since 6 June, hybrid earthquakes were detected; IGP noted that this seismicity can be attributed to rising magma. During 6-10 July, a daily average of 11 hybrid earthquakes was recorded. In the past few weeks, volcano-tectonic (VT) earthquakes migrated closer to the volcano, especially when the locations were compared with those from 2013. Within a week, the concentration of VT earthquakes had moved ~10 km closer to the crater, reaching a distance ~6 km N of the crater. This activity prompted IGP to install a new seismometer to augment their monitoring capabilities, now comprising six seismometers.

From mid-June through 10 July, fumarolic activity continued and white plumes were visible, although with less intensity within the last two weeks. Seismicity increased during this time period, particularly on 30 June and 1 July when a daily average of 87 LP earthquakes was recorded. From 27 June through 6 July, there was a daily average of 44 VT earthquakes. VT earthquakes were also occurring close to the crater. There were three persistent clusters of VT earthquakes near the crater: 6 km N, 16 km NE, and 10 km E.

Source: Instituto Geofísico del Perú (IGP)


8 May-14 May 2013 Citation IconCite this Report


On 10 May Instituto Geofísico de Perú (IGP) reported that results of an interferogram of Sabancaya provided by a collaborator at Cornell University showed that an area of deformation (subsidence of 7 cm centered at 6 km NE of the crater) was coincident with the main area of seismicity. Volcano-tectonic (VT) earthquakes continued to dominate the seismic signals, although long-period (LP) events continued to be detected. There was also an increase of hybrid events. On 10 May a M 4 VT event occurred 15 km W and fumarolic activity increased, with plumes rising 1.2 km high.

Source: Instituto Geofísico del Perú (IGP)


3 April-9 April 2013 Citation IconCite this Report


On 4 April Instituto Geofísico de Perú (IGP) reported that volcano-tectonic (VT) earthquakes at Sabancaya dominated the seismic signals although long-period (LP) events continued to be detected.

Source: Instituto Geofísico del Perú (IGP)


27 March-2 April 2013 Citation IconCite this Report


In an Instituto Geofísico de Perú (IGP) report, a photo showed a fumarolic plume rising above Sabancaya on 8 March. During the third week of March, a bluish colored plume rose 500 m above the crater, possibly indicating sulfur dioxide emissions. On 25 March the seismic network detected a continuing high rate of volcano-tectonic (VT) earthquakes and an increasing number of long-period (LP) events. On 27 March and 1 April VT earthquakes continued to be dominant and located below the NE sector of the crater. The number and amplitude of LP events did not change.

Previously, residents of Sallalli, 11 km S of Sabancaya, reported that fumarolic activity had increased on 5 December 2012. Four earthquakes within 15 km of the crater during 22-23 February caused damage in Maca, 20 km NE. In response, the Instituto Geofísico de Perú (IGP) installed seismic stations and recorded hundreds of earthquakes per day.

INGEMMET also installed monitoring equipment, and in partnership with IGP increased monitoring efforts. On 27 February scientists observed that the emissions were mostly water vapor, carbon dioxide, and sulfur dioxide. During 28 February-5 March there were 400-500 earthquakes per day recorded, mostly volcano-tectonic events.

Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET); Instituto Geofísico del Perú (IGP)


13 March-19 March 2013 Citation IconCite this Report


INGEMMET reported that during 24 February-6 March fumarolic emissions from Sabancaya rose 400-1,000 m above the crater. On 27 February scientists who visited the volcano noted no ash deposits, and observed that the fumarolic emissions were comprised mostly of water vapor, carbon dioxide, and sulfur dioxide. During 28 February-5 March there were 400-500 earthquakes per day recorded, mostly volcano-tectonic events. The temperature of La Calera hot spring was unchanged from the previous year. The Alert Level remained at Yellow.

Source: Instituto Geológico Minero y Metalúrgico (INGEMMET)


20 February-26 February 2013 Citation IconCite this Report


According to news articles, INGEMMET recorded 536 earthquakes from Sabancaya, or about 20 per hour, during 22-23 February. About 80 homes were damaged by the earthquakes, causing some evacuations. A plume rose 100 m; plumes had been intermittently visible since 15 January.

Source: Reuters


Bulletin Reports - Index


Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

06/1988 (SEAN 13:06) Increased fumarolic activity

05/1990 (BGVN 15:05) Ash eruption; plume to 7 km

06/1990 (BGVN 15:06) Ash emission continues; plume to 3-5 km

07/1990 (BGVN 15:07) Ash emissions decreasing in intensity; more information on June activity

05/1991 (BGVN 16:05) Vigorous Vulcanian activity; mudflows force daily clearing of river channel

07/1991 (BGVN 16:07) Earthquake swarm damages towns and triggers mudslides; 20 people reported dead

01/1992 (BGVN 17:01) Increased activity prompts official alert; ashfalls force evacuation of nearby towns

03/1994 (BGVN 19:03) Moderate Vulcanian activity continues; hazard maps completed

05/1995 (BGVN 20:05) Continuing activity, eleven eruptions observed during 9-10 May

07/1997 (BGVN 22:07) Quiet on 19 July; ash-bearing plumes on 1-2 May

05/1998 (BGVN 23:05) Summit activity, ice observed on visit in May

08/1998 (BGVN 23:08) Increases in August gas emissions

10/1998 (BGVN 23:10) Intermittent gas plumes in early September, some with ash

05/2000 (BGVN 25:05) During 28 April-10 May observers saw continuous gas plumes, some containing ash

05/2003 (BGVN 28:05) Inflation at Hualca Hualca detected by satellite surveys from June 1992 to April 1996

01/2004 (BGVN 29:01) New ashfall during July 2003

02/2013 (BGVN 38:02) Increased seismic and fumarolic activity in late 2012 and early 2013

05/2016 (BGVN 41:05) Increased seismicity February 2013; explosive events in August 2014

05/2017 (BGVN 42:05) Eruption with continuing ash plumes began on 6 November 2016




Information is preliminary and subject to change. All times are local (unless otherwise noted)


June 1988 (SEAN 13:06) Citation IconCite this Report


Increased fumarolic activity

Sabancaya reportedly began strong fumarolic activity in December 1986 [see also 15:05]. Interviews with area residents indicated that glowing tephra ejections from the crater were visible at night. Seismicity was felt on the flanks but was not noticed at a distance of 15 km.

A summit photograph was taken 10 August 1987, 8 months after initial reports of activity, during a civil defense helicopter reconnaissance in response to requests from residents and local authorities. Light to dense steam emerged from several sources in a moat surrounding the central plug of the middle (of at least three) summit cone. The dome, moat, and surrounding pyroclastic cone were covered with thick ice and snow except in areas adjacent to steam emission.

Geologists observed the volcano 22-24 June 1988.

22 June (Banks, Hall, Salas, Mothes, and Huaman; at 40 km distance with binoculars.) Every 0.5-2 minutes, voluminous steam pulses, some with dark, basal "rooster-tails," rose 0.5-1 km above the summit. A yellowish plume streamed horizontally 10-15 km E. A dark area of several tens to hundreds of square meters was prominent on the NE slope adjacent to the source of the steam emission.

23 June (Hall, Salas, Mothes, and Huaman; at 15 km.) Activity was similar to 22 June with perhaps slightly decreased plume heights. Strong sulfurous fumes were reported by flank inhabitants. Some cattle had died in these areas, either directly from the fumes or after eating contaminated foliage.

24 June (Banks, Lazo, Portillo, Salas, Huaman, and Tejada; from a fixed-wing flight supported by the Fuerza Aérea del Perú in coordination with the Defensa Civil. Observations are preliminary and will be improved by analysis of photographs and geological investigations on the ground.) A continuous annular crack encircled the outer flanks of an old pyroclastic cone. Weak to moderate fumarolic activity emitted vapor along the annular crack and the dome's edges. Frequent steam emissions (every 1-2 minutes) rose 0.3-5 km and originated from a vent in the moat on the SE side of the dome. Emission energy was substantially less than on 22 June. Some ejection events were lightly colored with ash but no "rooster-tail" forms were noted. Initial white steam pulses dissipated 500 m above the crater, but a yellowish plume streamed more than 10 km E. There was ~ 20-50 x 106 m3 of ice and snow on Sabancaya, a substantial decrease since the August 1987 observations. A bare area, devoid of snow and ice, surrounded the annular crack at variable distances averaging 50 m. Snow beyond this bare area was lightly dusted with ash, particularly on the SE side nearest the pulsing steam vent. Fresh sulfur surrounded many of the fumaroles. Several tens of meters in the bare area, S of the summit, were yellow. No crater lake was observed in the moat between the central dome and the surrounding pyroclastic cone. No new lava or bomb craters were observed. Sabancaya appeared to be built on a pile of young, thick, blocky lava flows and domes erupted from a vent on the mid-NE flanks of the larger Ampato volcano (figure 1). No thick pyroclastic deposits were obvious on Sabancaya or Ampato.

Figure (see Caption) Figure 1. Map of Sabancaya and Ampato showing the plateau, drainage system, and villages to the SE. Contour interval, 50 m. From the Chivay sheet (1:100,000), Instituto Geográfico Militar, 1980.

25 June (at 30 km from Aeroperú flight.) Activity was greatly diminished relative to that of 24 June.

Information Contacts: N. Banks, CVO; M. Hall, Instituto Geofísico, and P. Mothes, Defensa Civil liaison, Quito, Ecuador; M. Lazo, G. Salas Alvarez, and H. Portillo, Univ Nacional de Arequipa; D. Huaman, Instituto Geofísico del Perú, Lima; M. Tejada, Tercera Region Defensa Civil, Arequipa.


May 1990 (BGVN 15:05) Citation IconCite this Report


Ash eruption; plume to 7 km

Sabancaya is the youngest of a group of four stratovolcanoes . . . (figures 2 and 3). Weak solfataric activity from vents within and outside the summit crater has continued at Sabancaya for many years, . . . . Increased fumarolic activity began in 1985, and a September 1986 helicopter overflight by Alberto Parodi revealed that part of the ice cap had melted and sulfur was being precipitated by the fumaroles. According to area residents (roughly 4,000 people live on or near the volcano, and many more in valleys draining the edifice), strong fumarolic activity and ejection of glowing tephra began in December 1986. Frequent pulses of steam, minor ash emission, and a strong sulfur odor (noted by area residents) were reported by visiting scientists in June 1988 (13:6). By April 1989 the plume had reached 800 m height and the ice cover was significantly reduced (Guido Salas estimated in June 1990 that the ice cover was 20-40 x 106 m3). Activity then gradually increased through May 1990.

Figure (see Caption) Figure 2. Sketch map of SE Perú (box on inset map) showing the locations of Sabancaya and nearby volcanoes (triangles), and towns and rivers in the region. Pilots were warned of eruption cloud hazard along high-altitude routes UB677 and UB679 in the 5 June Notice to Airmen (NOTAM). Low-altitude air routes (W23, W25, and W26) and reporting points (ATIPA, VUGAL, and NEVDO) covered by the 5 June NOTAM are not shown.
Figure (see Caption) Figure 3. Portion of the Chivay 1:250,000 sheet (SD 19-13, Instituto Geográfico Nacional, Lima, Perú, 1988), showing Sabancaya, Ampato, Hualca-Hualca, and Ahuashune volcanoes, nearby towns, and the upper Colca river valley. Contour interval, 100 m.

Eruption begins, 29 May. A loud sonic boom on 29 May signalled the onset of periodic explosions at the volcano. From 29 May to 3 June, 2-3 explosions occurred/day with 700-800-m column heights. The eruption plume had a strong sulfur odor. A 1 June press report noted that residents of Maca, 18 km NE of the volcano on the Río Colca, heard underground noises and smelled sulfur (see also 6 June). Two additional seismographs were installed on 3 June and increased seismic monitoring was begun (one seismograph had been installed ~ 10 km SW of the crater in 1989). By 3 June, the plume's height had increased to 1 km and it was blowing SSE (figure 4).

Figure (see Caption) Figure 4. Tephra cloud from Sabancaya, viewed from the E on 3 June 1990. Ampato volcano is at left. Photo by Ch. Pattry, courtesy of Alberto Parodi.

Intensity increases, 4 June. Residents at the base of the volcano reported that explosions had increased to 1 every 20 minutes with a strong sulfur odor and higher noise levels. Ash emission was reported to be continuous, with a column height of 2 km and pulses every few minutes. The plume appeared water-rich, dark gray, and blew NE and ENE, with dense ashfall to 5 km and light ashfall as far as 10 km downwind. Frequent earthquakes were reported.

5 June. The eruption intensity continued to increase, becoming essentially continuous with column heights of 3-6 km. Glowing tephra ejection was reported. The continued ash emission reportedly was seriously affecting grazing land within 10 km of the volcano. Residents in scattered settlements were advised to evacuate at once and remove livestock (llamas and alpacas); many people were reported to have already left. A NOTAM was issued at 1730 stating that routes in the Sabancaya area were affected by the plume, just over 9 km asl (roughly 3 km above the summit).

7 June. The Corporation for Airports and Commercial Aviation requested airlines regularly flying over south Perú to modify routes and issued specific warnings to Perúvian airlines flying to Arequipa. They reported a column to 7 km above the summit. The press reported that the plume headed toward Arequipa and Puno with ash continuing to fall up to 20 km away, destroying pastures and crops, and contaminating the Río Sihuas to the south. Earthquakes were felt at 3-minute intervals in the towns of Chivay (30 km NE of Sabancaya), Maca (18 km NE), Lari (20 km NNE), and Achoma (22 km NE). The press also reported that "crevices with sulfur emanations opened on the ground" in Maca.

8 June. Violent explosions occurred every 5-10 minutes, ejecting pyroclastic material, mainly fine ash, to 1 km height. Ash was reported to cover an area with a radius of 20 km at accumulations up to 1 cm thick. No new lava or juvenile material had been identified. The explosions were accompanied by felt shocks and dull rumbling. The seismic network measured 5-6 microearthquakes/day. Satellite wind data on 11 June indicated that surface winds were from the S, winds at ~ 8 km altitude (372 mbars) were from the NW (298°) at 32-38 m/s (60-70 knots), and winds at >10 km (200 mbars) were from the WNW at 40 m/s (75 knots). As of 17 June, eruptive activity appeared to be continuing to increase.

Information Contacts: A. Parodi, Arequipa; N. Banks, CVO; M. Casaverde, A. Rodriguez, and E. Deza, Instituto Geofísico del Perú, Lima; R. Kosaka, G. Salas Alvarez, and M. Lazo, Univ Nacional de San Agustín, Arequipa; A. Giesecke, CERESIS, Lima; N. Krull, FAA; S. Hamerla, SAB; EFE network, Madrid, Spain; Agence France-Presse; Reuters.


June 1990 (BGVN 15:06) Citation IconCite this Report


Ash emission continues; plume to 3-5 km

Sabancaya continued to eject ash through late June. Pulses of volcanic gas and ash were emitted at roughly 30-minute intervals, reaching 1-3 km above the summit. Ashfall appeared to be limited to a 10-km radius. Accumulations of several tens of centimeters were reported on the ice/snow cap that covers ~ 4 km2 of the summit area. No juvenile material was evident in a preliminary petrographic examination of the ash. An average of 15 high-frequency (A-type) events were recorded daily. The seismic network consisted of two seismometers 22 km NE and NW of Sabancaya, with an additional seismometer being installed on the S side of the volcano. A 1:100,000 scale hazard map was produced by the Univ Nacional de San Agustín and Civil Defense officials. Towns in the 1,500-m-deep Colca Valley, 20 km N of the volcano, are perched above the valley floor and not at much apparent risk from lahars or other volcano related flows. Although between 8,000 and 10,000 people were living in other drainages in the area, all were at least 25 km away. Field geology showed one old lava flow to be hornblende-rich high-Si andesite/dacite in composition. Pits dug at the volcano's E base yielded only alluvium, with no recent volcanic deposits.

Information Contacts: M. Hall, Instituto Geofísico, Quito, Ecuador; N. Banks, CVO.


July 1990 (BGVN 15:07) Citation IconCite this Report


Ash emissions decreasing in intensity; more information on June activity

A joint mission by Minard Hall, Escuela Politécnica Nacional, Quito, Ecuador, and scientists from the Instituto Geofísico del Perú (IGP) and the Univ Nacional, San Agustín (UNSA) in Arequipa, was conducted 16-24 June to evaluate the status of activity at Sabancaya. The following is Hall's report on the mission (translated by John Ewert) which supplements information in 15:5-6.

"The first indication of the reactivation . . . began in December 1986 with the appearance of summit crater fumarolic activity, which increased during 1988. In June and July 1987, a swarm of felt earthquakes was reported in the region but could not be confirmed. During a visit to the area by the [USGS] Volcano Disaster Assistance Program and the author in June 1988, the inhabitants of Huanca (25 km S from Sabancaya) reported that nothing new had occurred at the volcano other than an increase in summit fumarolic activity.

"On 28 May 1990, the inhabitants of the region informed Civil Defense of an eruption . . . consisting of a steam and ash plume that ascended several kilometers above the volcano. IGP and UNSA were informed at the same time. More intense activity was reported 2-4 June, leaving a thin (1 mm) deposit of ash in the valley E of the volcano. From 12 June until this writing (23 June) the volcano has apparently shown the same level of activity, consisting of violent emission of gases and ash forming a light-gray to medium-gray cloud that rose 2-3 km above the summit. Emissions lasted less than a minute before stopping and typically occurred every 20-30 minutes. Between emissions the volcano maintained a vapor plume several hundred meters high.

"During the mission a trace of gray ash fell over an extensive area to the N, NE, and E of Sabancaya, causing considerable worry among the inhabitants. Nevertheless, the quantity of ash that has fallen since 12 June is not significant and we confirmed that only 1 cm of ash had accumulated at the E foot of the cone since that date. All of the cone, including its snow and ice, is covered with several centimeters of ash. The two neighboring volcanoes are also covered with a trace of gray ash. It should be noted that neither of these neighboring volcanoes are displaying abnormal activity."

Since the time of Hall's report, there has been a gradual decrease in activity (column height and frequency of explosive events) at Sabancaya.

Information Contacts: M. Hall, Instituto Geofísico, Quito, Ecuador; N. Banks, CVO.


May 1991 (BGVN 16:05) Citation IconCite this Report


Vigorous Vulcanian activity; mudflows force daily clearing of river channel

Strong Vulcanian explosions were observed during a visit on 13-19 April. The explosions, occurring every 20-30 minutes, lasted ~ 1 minute and produced 3-4-km-high, medium-gray ash clouds. Small avalanches were produced by falling blocks at the base of the eruptive columns. Quiet degassing continued between explosions. Light-gray ashfall was frequent during the visit, depositing 2 mm one night ~9.5 km SE of the summit (at Cajamarcana).

The volcano began erupting in late May 1990, reportedly ejecting ash to 7 km. By late June 1990 (15:7), activity had decreased to periodic explosions with weak ash columns 2-3 km high, but then increased slowly through November. High-frequency seismicity (>122 events recorded over one 2-week period) was usually centered ~ 10 km NE, although two earthquakes occurred under the crater. Several tremor episodes were recorded, starting in October.

The plume was black and heavy with ash during an overflight on 10 November, rising an estimated 5-8 km in distinct, but almost continuous pulses. Ash deposited on Hualca Hualca (4 km N) caused increased melting of the glaciers (estimated 20 cm of snow above the ice and berm) producing numerous mudflows. These moved down the N flank nightly, dumping an estimated 13,000 m3 of debris/day into the Majes River drainage system ~ 5 km N of the volcano. Construction crews cleared the channel daily. Airfall deposits were composed of 80% lithics and 20% glassy fragments and breadcrusted material. At one outcrop, the 1990 ash accumulations were 1 cm thick, overlying at progressively greater depth 30 cm soil, 2 cm ash, 40 cm soil, and another 2 cm ash. Eruptive activity observed on 22 December appeared about the same as it was on 10 November.

Information Contacts: P. Vetsch and R. Haubrichs, SVG, Switzerland; N. Banks, CVO; Instituto Geofísico del Perú, Lima.


July 1991 (BGVN 16:07) Citation IconCite this Report


Earthquake swarm damages towns and triggers mudslides; 20 people reported dead

A swarm of earthquakes, reported on 23-24 July, triggered mudslides that partly buried four villages. In towns within 20 km N of the volcano, the earthquakes caused many houses to collapse, especially in Maca (15 km N) which was almost completely destroyed. The press reported that 20 people were killed, 80 were injured, and 3,000 were left homeless. More than 20 earthquakes/day were reported felt (MM <=V) 75 km SE (in Arequipa). The largest of the shocks (Ms [4.7]), detected at [1444] on 23 July by the WWSSN, was centered [35] km [ENE] from the volcano at shallow depth.

Information Contacts: NEIC; EFE network, Madrid, Spain; Agence France-Presse; Reuters; UPI; AP.


January 1992 (BGVN 17:01) Citation IconCite this Report


Increased activity prompts official alert; ashfalls force evacuation of nearby towns

The press reported that the Instituto Geofísico del Perú and Civil Defense officials declared an "alert" on 19 February, following increased activity at the volcano. Gas and ash from the 4.5-km-high plume had reportedly caused respiratory problems and covered homes and crops during the previous several months, prompting people to evacuate several towns within a 14-km radius of the volcano. The press also reported that several small streams of "lava" had moved downslope during the previous few days. Seismicity at the volcano had increased to as many as 50 earthquakes recorded daily. Vulcanian activity has continued at varying intensity (ash clouds 2-7 km high) since the start of the eruption in late May 1990.

Information Contacts: A. Giesecke, CERESIS, Lima; N. Banks, CVO; AP.


March 1994 (BGVN 19:03) Citation IconCite this Report


Moderate Vulcanian activity continues; hazard maps completed

Fieldwork was conducted on 4-8 March by scientists from the Univ Blaise Pascal (Clermont-Ferrand, France), the Instituto de Geofisico del Perú (Arequipa, Perú), and the Univ de Liège (Belgium). The purpose of the visit was to observe current activity, assess eruptive hazards, and collect samples of juvenile material. The joint mission investigations included the geology and geomorphology of the summit domes and block-lava flows, the role played by explosions on the morphology of the summit, crater, and ice cap (fracturing, gullying, tephra-fall cover, and mudflows), and analysis of tephra, lavas, and ice.

An ash explosion was observed early in the morning on 5 March from Sallili (8 km E at the base of the volcano). The eruption column rose for 30 seconds to a height of 2.5 km and generated a dark gray plume that was blown W. A vapor-rich explosion ~ 2.5 hours later produced a dominantly white plume that rose 1.5 km. Between these explosion there was a discrete vapor plume above the crater. Another early morning explosion on 7 March lasted for about 60 seconds and fed a dark gray plume 1.5 km high. Dominantly white plumes later that morning rose 1-2 km.

Activity of a similar nature has been exhibited since December 1992, with strong explosions of gas, ash, and blocks forming a gray or light-gray plume rising 1-3 km above the summit. Explosions have occurred every 1-2 hours (20-30 minutes in late 1992), and generally lasted <1 minute. Residents of Sallili have seen glowing projections at night since autumn 1993. Observations in December 1992 (Salas and Thouret) indicated that the crater had widened.

The 1990-92 tephra represent a small bulk volume (0.025 km3), but are widely dispersed around the crater; ballistic blocks reached a few hundred meters, and ash as far as 20 km. The juvenile component belongs to a K-rich calc-alkaline series and is compositionally variable from andesite (58% SiO2) to dacite (63% SiO2). The mineral assemblage of 1990-93 juvenile magma consists of plagioclase, green pyroxene, brown amphibole, biotite, destabilized olivine, and Fe-Ti oxides. Since 1990 the juvenile component has increased from 15 to ~50% by volume. Ejecta consist of black, vitreous, slightly vesicular andesitic fragments and gray dacitic fragments. Glassy black blocks with radial fractures dominate the 1994 tephra. Although the geochemical difference between the andesite and dacite is small, mineralogical disequilibrium suggests an interaction between two magma batches. One was more felsic than the dacite and included oligoclase and hypersthene; the other was more mafic than the andesite and included labradorite, bronzite, and olivine.

Hazard assessment and hazard-zone mapping has been done based on geological and geomorphological data, photo interpretation, remote sensing, and models of tephra dispersion (Thouret and others, 1994). Hazard zones are defined for tephra-fall, pyroclastic flows, lahars, and potential catastrophic events. These zones are portrayed for moderate Vulcanian activity (1990-94), growth of a dome and/or emission of a blocky lava flow, possible increase of Vulcanian activity (including small-scale pyroclastic flows), and a potential large Plinian event. Geological study and remote sensing of the current activity have provided a sound basis for evaluating and mapping hazards at and around Sabancaya. Holocene block-lava flows cover as much as 40 km2 around the summit domes. Thin Plinian tephra-fall deposits from historical eruptions are found as far as 11 km from the crater, and block-and-ash pyroclastic-flow deposits as far as 7 km from the source. Recent lahars have traveled ~25 km downstream.

Unstable lava domes pose a threat for ~35,000 people living in the Rio Colca and Siguas valleys. Sabancaya is still ice-clad (currently estimated to be 3.5 km2 of glacial ice) despite its recent 4-year period of activity. The Majes River irrigation canal project is also at potential risk should a moderate-to-large eruption melt the ice and snow on Sabancaya and Ampato.

Reference. Thouret, J-C., Guillande, R., Huaman, D., Gourgaud, A., Salas, G., and Chorowicz, J., 1994, L'activité actuelle du Nevado Sabancaya (Sud-Pérou): reconnaissance géologique et satellitaire, évaluation et cartographie des menaces volcaniques: Bull. Soc. Geol. France, v. 165, no. 1, p. 49-63.

Information Contacts: A. Gourgaud, F. Legros, and J-C. Thouret, Univ Blaise Pascal, Clermont-Ferrand, France; G. Salas, Univ San Augustine, Arequipa; A. Rodriguez and M. Uribe, Instituto de Géofisico del Perú, Arequipa; E. Juvigné, Univ de Liège, Belgium.


May 1995 (BGVN 20:05) Citation IconCite this Report


Continuing activity, eleven eruptions observed during 9-10 May

During a 2-day visit to Sabancaya, 11 eruptions were witnessed, 5 on 9 May and 6 on 10 May. The repose periods varied in duration from 35-160 minutes, with a mean of 125 minutes on both days. All of the eruptions started with the quiet emission of a white vapor plume followed tens of seconds later by a rapidly rising cloud of vapor and ash. Each eruption progressed from the S vent to the two N vents, and typically lasted 5-15 minutes.

Throughout the eruptions only a few blocks were ejected from the crater as seen from the foot of the cone, ~500 m from the crater rim. No "cannon-like" explosions were seen or heard. The talus apron at the foot of the cone consisted mainly of dense blocks with abundant thermal cracks, and minor amounts of poorly vesiculated scoria.

Plume height varied between 1 and 4 km above the crater, though usually the plumes rose ~2-2.5 km. Eruptions were typically followed by emission of a quiet, slowly rising white-blue plume; these plumes drifted to the SW and S on 9 May and S and E on 10 May. The presence of ash on Sabancaya and the adjacent Ampato volcano caused enhanced ice-melting during daytime hours, creating continuous small mudflows.

Although observations were not as detailed, activity on 11 May was apparently much less than on 9-10 May with only three reported eruptions, one being purely phreatic (white vapor).

Vulcanian activity has persisted at varying intensity levels since ash emission began in late May 1990 (BGVN 15:05, 15:06, 16:05, and 17:01). During the previous visit to the volcano in March 1994 (BGVN 19:03), scientists observed explosions, classified tephra layers, and carried out hazard-zone mapping. Unstable lava domes continue to threaten the 35,000 inhabitants living in the Rio Colca and Siguas valleys. Sabancaya remains ice-covered and poses a potential risk to the Majes River irrigation canal project if a moderate-to-large eruption were to occur. Of particular concern is an eruption that might melt the ice on both Sabancaya and Ampato volcanoes.

Information Contacts: Jean-Luc Le Pennec, Centre ORSTOM de Brest, BP 70, 29 280 Plouzane, France (Email: jlpennec@ifremer.fr); Francois Legros, Universite Blaise Pascal, Departement des Sciences de la Terre, 5 rue Kessler, 63038 Clermont-Ferrand, France; Anibal Rodriguez and Miguel Uribe, Instituto Geofísico del Perú, Arequipa, Perú; Jean-Claude Thouret and Alain Gourgaud, Centre de Recherches Volcanologiques, 5 rue Kessler, 63038 Clermont-Ferrand, France.


July 1997 (BGVN 22:07) Citation IconCite this Report


Quiet on 19 July; ash-bearing plumes on 1-2 May

During a mid-[July] visit, Sabancaya displayed only fumarolic activity. Visiting scientists also examined the area well to Sabancaya's N along the Colca river. They determined that previous reports of destructive, seismically triggered mudslides in 1991 (BGVN 16:07) had been incorrect.

On 19 July scientists flew over Sabancaya and the two adjacent volcanoes Ampato and Hualca Hualca (figure 5) while taking slides and Super VHS images. Ice fields and snow cover were observed only on the summit regions of Ampato (6,288 m) and Hualca Hualca (6,025 m). Thus, the ice fields that existed on Sabancaya prior to the most recent eruption (29 May 1991, BGVN 15:05) had not returned.

Figure (see Caption) Figure 5. Map of the region around Sabancaya showing adjacent stratovolcanoes and the Colca river. This segment of the Colca river flows westwards. Courtesy of M. Bulmer, F. Engle, and A. Johnston, CEPS.

As the photo (figure 6) reveals, Sabancaya's cone remains nearly symmetrical with slopes of 30-40 degrees. The cone is roughly 1 km in diameter and contains a central crater with a diameter of approximately 400 m. Slope failure occurred along a ~600-m-long arcuate scarp seen on the cone's NE flank. This could prove to be a zone of weakness in any future eruption. An active fumarole was located at the summit cone in a spot on the wall of the southern crater rim; it vented rapidly. Less active fumaroles were seen on the western crater wall and sulfur deposits occurred on the upper crater walls. When the cone was viewed from a distance of 1 km, observers saw significant atmospheric aberrations that implied gas emissions.

Figure (see Caption) Figure 6. Aerial photo of Sabancaya taken on 19 July 1997 looking W. The crater is approximately 400 m in diameter. The surface of the cone is mantled in young ash deposits (not snow). Courtesy of M. Bulmer, F. Engle, and A. Johnston, CEPS.

In the Colca Valley scientists saw extensive damage from the 23-24 July 1991 earthquake swarm including abandoned, damaged buildings, and slope failures; what they failed to find, however, was evidence that mudslides had ravaged local villages. This was important because BGVN 16:07 briefly described seismic damage from the earthquakes but also stated that they ". . . triggered mudslides that partly buried four villages." Based on this latest visit, this latter statement was clearly incorrect; it may have stemmed from the cited press accounts.

The scientists visited the villages of Maca, Achoma, Yanque, Lari, and Chivay. The earthquake damage was greatest in Maca, which lies in the Colca valley below the NNE flank of Hualca Hualca, a spot 15 km N of Sabancaya. Particularly in Maca, there was abundant evidence of seismically induced damage to structures. It should be noted that most buildings in the region had been constructed with walls made of loose stone without the benefit of concrete mortar or steel reinforcing.

On the NW side of Maca the group found evidence for a series of rotational and translational slides and slumps triggered by 2 m of throw along a normal fault. There was a series of well defined backscarps delineating different slope failures (figure 7) that extended ~1 km from the NW margin of Maca down to the Colca river. No houses were located on the failed surfaces; instead, this area had been terraced for agricultural use, but it was fallow when visited. The failure "complex" remained mobile and its toe was being undercut by the river. The village of Maca was being rebuilt gradually as people returned to the area. Some of the new housing includes concrete structures but most are made of adobe (clay and straw) brick with corrugated sheet-metal roofing.

Figure (see Caption) Figure 7. Aerial photo of Sabancaya taken on 19 June 1997 looking SE; it shows slope failures located NW of the village of Maca. The Rio Colca is visible in the lower part of the image. Note the road running across the upper third of the photo (trending E-W); it had to be realigned near Maca. Maca's market square can be seen in the upper left side of photo. Courtesy of M. Bulmer, F. Engle, and A. Johnston, CEPS.

Prior to the visit, on 1 and 2 May, aviation reports described ash-bearing plumes. The plume on 1 May reportedly reached ~5.5-km altitude; the one on 2 May, ~7.3-km altitude.

Information Contacts: M.H. Bulmer, F. Engle, and A. Johnston, Center for Earth and Planetary Studies (CEPS), National Air and Space Museum, Smithsonian Institution, Washington, DC 20560 USA (Email: mbulmer@ceps.nasm.edu); Guido Salas, Universidad de San Agustin, Casilla 1203, Arequipa, Perú; A. Seimon, Department of Geography, University of Colorado, Boulder, CO 80309-0260 USA; NOAA/NESDIS Satellite Analysis Branch (SAB), Room 401, 5200 Auth Road, Camp Springs, MD 20746, USA; Tom Fox, Air Navigation Bureau, International Civil Aviation Organization (ICAO), 999 University St., Montreal H3C 5H7, Canada (URL: http://www.cam.org/~icao/).


May 1998 (BGVN 23:05) Citation IconCite this Report


Summit activity, ice observed on visit in May

Sabancaya was observed by scientists of the National Air and Space Museum's Colca Valley Geohazard Project during a four-day visit (18-21 May) made in preparation for field work later in the year. Continuous fumarolic activity at the E side of the crater rim was observed during this visit. Seasonal snow patches were visible on the SE flank that were not present when the team made an aerial observation in July 1997 (BGVN 22:07).

On 18 May a seismic event was noted by observers traveling in a vehicle on the Pampa Lliullipampa, SE of the volcano. The disturbance produced a dust cloud that spanned the entire Ampato-Sabancaya-Hualca Hualca complex along its E slopes, a distance of 15 kilometers. A video camera recorded the disturbance at 1525 on 18 May. Roughly concurrently, scientists at the Instituto Geofísico in Arequipa detected a deep focus M 6 earthquake centered 250 km to the N near Ayacucho. Tremors occurred at this time in the pueblo of Cabana Conde located 15 kilometers NW of Hualca Hualca.

On 20 May A. Seimon of the University of Colorado ascended Sabancaya's SE flank and recorded a video of the fumarolic activity inside the crater rim, including the steady emission of gas from the crater floor (figure 8). He noticed ice along the route up the E flank. The ice lies beneath a layer of ash 5 to 10 cm thick, a depth that seemed sufficient to insulate it from higher surface temperatures. Ice was also observed filling a breach in the N side of the crater rim.

Figure (see Caption) Figure 8. Video frame showing the inside of the S rim of Sabancaya's crater. The fumarole was continuous during the observation period (18-21 May). Snow-covered Nevado Ampato is visible beyond the crater rim. Courtesy of A. Seimon.

Sabancaya is the youngest of the three adjacent stratovolcanoes located 75 km NW of Arequipa. The volcano's 29 May 1990 eruption produced a plume reaching a maximum height of 7 km (BGVN 15:05). The plume traveled NE and carried fine ash that fell up to 20 km away. Extensive mudflows (not mudslides) had occurred in the area in the months after the Sabancaya eruptions that began in late May 1990. These mudflows resulted from fallen ash and the subsequent melting of snow and ice on Hualca Hualca (BGVN 16:05; v. 15, no. 5).

Information Contacts: F. Engle, Center for Earth and Planetary Studies (CEPS), National Air and Space Museum, Smithsonian Institution, Washington, D.C. 20560 USA (Email: engle@ceps.nasm.edu); A. Seimon, Department of Geography, University of Colorado, Boulder, CO 80309-0260 USA; S.O. Brooks, Department of Geography, University of Wisconsin, Madison, WI USA 53706-1491.


August 1998 (BGVN 23:08) Citation IconCite this Report


Increases in August gas emissions

Activity was monitored during 13-31 August using satellite remote sensing data and detailed field observations. During this time, the amount of gas being emitted from the central crater increased. At the height of emission, gas clouds from the crater rose over 1 km. Most frequently, plumes attained heights of 300-500 m before dissipating due to strong winds. However, on several occasions cumulo-type clouds formed and moved over the surrounding Pampa. Gas emissions were predominantly white in color but occasionally gray, yellow, and brown. During active phases new plumes emerged on average every 2-3 minutes. Nearly continuous venting occurred from two fumaroles on the N and S sides of the crater.

At 0640 on 16 August a pronounced increase in gas emission was observed. Dense white clouds filled the crater and formed a plume rising over 300 m. At 0645 material was seen falling from a gray/brown cloud onto the S flank of the cone. This small ash ejection lasted for a few minutes (figure 9). A noticeable decline in the emission rate occurred from 0726 until 0847, when gas clouds became infrequent. Activity continued at this reduced level into the next day. At 1355 on the 18th a yellow/brown and gray cloud rose ~800 m above the crater. Following this, activity returned to faint gas emissions. Increased activity was observed again at 1019 on the 20th when dense yellow and brown clouds were emitted. Another thick brown gas cloud emerged at 1044, after which there was a return to white emissions. Activity decreased noticeably from 1100 to 1200, by which time the gas was only faintly visible. On the 22nd at 1420 dense white clouds rose 500 m over the crater. Plumes emerged predominantly from the S side of the crater every 2-3 minutes.

Figure (see Caption) Figure 9. A ground view of one of the small ash eruptions at Sabancaya on 16 August at 0700 looking to the NW. Ash fell on the S side of the upper slopes of the cone. Courtesy of Mark Bulmer.

No emissions were seen on 23 August until 1325; a large dense gas cloud emerged from the whole crater at 1510. At 1524 the cloud on the S side of the crater formed a brown plume that rose straight upwards more than 400 m. Gas clouds descended the upper S slopes of the cone at 1530. Five minutes later a light brown-white and yellow gas plume formed on the N side of the crater. Emissions continued until dusk when observations ceased. On the morning of the 24th at 0740 dark gray clouds rose slowly from the crater. At 0756 gas from the lower portion of an ascending plume moved down the upper slopes of the cone on the N side. By 0804 the color of the plumes emerging from the crater altered to white. However, at 0816 a gray/brown gas cloud emerged and dispersed <100 m above the crater. After this no further emissions were seen until 1359 when white emissions commenced, forming cumulo-type clouds that sat over Ampato. At 0700 on the 25th, dark gray and brown clouds were emitted from the center of the crater. At 0714 a white, brown, and gray cloud emerged from the middle of the crater. Emissions were light for the rest of the day.

On 26 August at 0757 a light brown-and-gray cloud emerged. Only faint emissions were noted until 0804 when a new brown and white cloud rose 300 m. The amount of gas released then diminished to very small clouds every 2-3 minutes. At 1430 gas was rising from the whole crater; activity remained at a similar level for the rest of the afternoon. At dusk, a brown haze sat over the crater. Only limited observations were possible on 28 August. Activity was first noted at 0857 when a gray cloud emerged from the S side of the crater. Gas emission was observed at 1430 but not at 1630. The next observation was at 1447 on the 31st, at which time white clouds were being emitted from the center of the crater. At 1625 the amount of gas being released appeared to increase and became grayer. Evening sunlight was seen refracted in gas clouds ~1 km above the crater, producing a rainbow effect.

Information Contacts: Mark Bulmer, Frederick Engle, and Andrew Johnston, Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, Washington DC 20560-0315 (Email: mbulmer@ceps.nasm.edu).


October 1998 (BGVN 23:10) Citation IconCite this Report


Intermittent gas plumes in early September, some with ash

Activity was monitored during 1-9 September using detailed field observations combined with satellite and aerial remote sensing data. Activity was generally similar to that reported in August. On 6 September a large eruption began. In the preceding days activity had fluctuated. On 1 September, the only activity observed was a small white gas cloud at 0944. Gas clouds were emitted from 0748 until 0942 on 2 September. These predominantly white and gray clouds rose only 200 m above the crater before dissipating. The only exception was a period of ten minutes when brown and dark gray clouds issued from the crater. The sole emission the following day was a small white gas cloud at 1506. On 4 and 5 September small gas emissions were observed from the fumarole on the S side of the cone.

Activity on 6 September was first noted at 0702 when large white and gray gas clouds rose from the whole crater. At 0704 part of the gas column began to sink and move down the upper flanks, obscuring the E-flank ice walls. The gray and brown gas cloud was densest on the S side of the crater and appeared to be expanding as it rose. At 0711, the whiter part of the cloud rose upward while the dark gray portion dropped ash on the N side of the cone. Wind speeds at the summit appeared to increase, and the 400-m-high column began to be pushed N. At 0716 more gas descended the flanks. At 0735 observers on the edge of the easternmost lava flow could smell sulfur.

The main gas emission continued to be from the S side of the crater and at 0740 another cloud descended over halfway down the flanks. At 0743 a large white and dark gray gas cloud emerged from the crater. Ash fell from it onto the upper and mid-slopes. Another large gray, white, and brown plume filled the whole crater at 0746 and billowing to 400 m. At 0749 the plume color changed to brown, yellow, and dark gray. Ash was blown N. New gas clouds emerged from the crater on average every 30 seconds. At 0824 the cloud color returned to white and light gray for a few minutes before it once again became brown, gray, and yellow. The brown portion seemed to contain the ash. Gas once again descended the upper slopes at 0846. Winds at the summit began to pull the top of the plumes apart and by 0854 they were almost flat across the crater.

There was a reduction in gas emission at 1143. Gas continued to periodically descend the upper slopes and ashfall appeared to be mainly on the N slopes. At 1155 a gas cloud descended to mid-slope. The interval between gas emissions grew during the afternoon. After three hours of white- and gray-colored gas clouds, yellow, white, and brown clouds emerged again at 1604. This marked renewal of activity was similar to that in the early morning. Gas originated mainly from the southern fumarole and occasionally descended the upper slopes. Gas clouds rose 500 m and formed a cumulo-like mass. At 1737 there was a big gas release, part of which descended the cone slope while the main cloud rose and curled N over the crater. After this the intensity of the activity from the cone diminished and gas clouds became light gray.

On 7 September a faint brown haze was noted over Sabancaya at 0630. Dust in the atmosphere obscured viewing. Gas clouds were observed at 0643, 0704, 0719, and 1210. Visibility improved around mid-day, and ashfall was observed on the S side of the cone at 1243. At 1652 a small gas cloud descended the upper slopes. From 1740 until dark, gas emissions were continuous, but none were seen the following day. On 9 September observers on a morning flight around the volcano observed light emissions from fumaroles on the N and S crater rims. Fresh sulfur deposits existed on the crater walls. The crater itself was deeper than the year before and the floor could not be seen. Recent ash eruptions had covered the ice walls on the E side.

Information Contacts: Mark Bulmer, Frederick Engle, and Andrew Johnston, Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, Washington DC 20560-0315 USA (Email: mbulmer@ceps.nasm.edu); Guido Salas, Departamento Academico de Geoloia y Geofisica, Universidad Nacional de San Augustin, Arequipa, Perú; Elian Perea, Universidad Nacional de San Augustin, Arequipa, Perú.


May 2000 (BGVN 25:05) Citation IconCite this Report


During 28 April-10 May observers saw continuous gas plumes, some containing ash

A team of geologists monitored Sabancaya from the settlement of Sallalli on the E flank of the volcano during the daylight hours from 28 April to 10 May. In this period, gas emissions from the active crater fluctuated but were less than those observed in 1998 (BGVN 23:08 and 23:09).

During much of the current visit, a continual background emission was observed rising from the whole crater. Vigorous activity also occurred from three fumaroles located on the S, E, and N rims of the crater. The fumarole on the S rim was most active, with emissions every 1-3 minutes, while the fumarole on the N rim was the most sporadic.

During periods of calm air, gas clouds the width of the crater rose 1,000 m before dissipating, but summit level winds often sheared gas clouds 200-300 m above the vent. Emissions were predominantly white in color, but occasionally were gray or brown and appeared to contain ash. Localized fresh ash deposits were observed on the S flank of the cone. Material was also observed cascading from the ice wall on the E side of the cone forming small talus aprons.

Strong sulfurous smells were noted on five separate days while observers conducted topographic surveys on the lava flows. These coincided with winds blowing downslope from the summit.

While in the town of Arequipa, the group visited the Universidad San Augustin and reviewed the seismic records for Sabancaya and the Colca Valley over the period 1987 to the present. These data failed to reveal any direct correlation between eruptions of Sabancaya and the succession of earthquakes that occurred in the Colca Valley during 1990-1991 (BGVN 16:07).

Frequent seismic swarms have occurred in the Colca Valley around the towns of Lari and Cabana Conde but have shown no correlation with the low level eruptions at Sabancaya. In 1991, the local press (El Correo, 3 May, 1991) reported a correlation between a rise in the geothermal water temperature in the Colca Valley and the activity at Sabancaya but no geophysical data can be provided to support this correlation. Examination of the seismic records for Sabancaya suggests that the magma chamber is isolated.

Information Contacts: Mark Bulmer, Center for Earth and Planetary Studies, National Air and Space Museum, Washington DC 20560-0315 (Email: mbulmer@ceps.nasm.edu); Tracy Gregg, Department of Geological Sciences, SUNY Buffalo, NY 14260-3050; Stephen Metzger, Department of Geology, University of Nevada Reno, NV 89557; Steve Schubring, Department of Geography, Geology, and Anthropology, Indiana State University, IN 47802 USA; Jeff Byrnes, Department of Geology and Planetary Sciences, University of Pittsburgh, PA 15260 USA; Guido Salas, Departamento de Geología y Geofísica, Universidad Nacional de San Agustín, Arequipa, Perú.


May 2003 (BGVN 28:05) Citation IconCite this Report


Inflation at Hualca Hualca detected by satellite surveys from June 1992 to April 1996

A satellite-based interferometric synthetic aperture radar (InSAR) survey of the remote central Andes volcanic arc (Pritchard and Simons, 2002) revealed deformation in the Sabancaya area during June 1992-mid 1997. Inflation was detected ~2.5 km E of the Hualca Hualca cone and 7 km N of Sabancaya (figure 16), with the maximum deformation rate in the radar line-of-sight being ~2 cm/year. While not temporally well-constrained, this inflation seems to have stopped in 1997, perhaps related to the large eruption of Sabancaya in May 1997 (BGVN 22:07). No deformation was observed between mid 1997-December 2001. The inferred source depth was 11-13 km below sea level. Additional details about the study and analysis are available in Pritchard and Simons (2002).

Reference. Pritchard, M., and Simons, M., 2002, A satellite geodetic survey of large-scale deformation of volcanic centres in the Central Andes: Nature, v. 418, p. 167-170.

Information Contacts: Matthew Pritchard and Mark Simons, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA (Email: matt@gps.caltech.edu, URL: http://www.gps.caltech.edu/).


January 2004 (BGVN 29:01) Citation IconCite this Report


New ashfall during July 2003

As previously reported in BGVN 28:05 no deformation had been observed during mid-1997 through December 2001. In mid-2003 observers saw evidence of recent ash emissions.

On 31 July 2003, during a commercial flight from Cusco to Arequipa, Mike Sheridan observed ashfall deposits on fresh snow at Sabancaya volcano. The flight path was S of the volcano on a cloud-free day, and fresh snowfall had occurred a day or two before. Ashfall deposits blanketed the cone's summit and, on the NE side, extended to the volcano's base. Two days later, when traveling by car, Sheridan and Jean-Claude Thouret observed the ash from the E. They saw ash down to ~ 5,000 m elevation. The ash blanket appeared comparable to those observed at Sabancaya in the 1990s.

Information Contacts: Michael F. Sheridan, SUNY at Buffalo, Dept. of Geology, Buffalo, NY 14260 (mfs@acsu.buffalo.edu); Jean-Claude Thouret, Centre de Recherches Volcanologiques, 5 rue Kessler, 63038 Clermont-Ferrand, France (Email: thouret@opgc. univ-bpclermont.fr).


February 2013 (BGVN 38:02) Citation IconCite this Report


Increased seismic and fumarolic activity in late 2012 and early 2013

Sabancaya volcano, located 72 km NW of Arequipa city, is one of the most active volcanoes of the Central Andes (figure 10). Our last report of Sabancaya described ashfall during July 2003 (BGVN 29:01). This report describes an increase in anomalous seismic and fumarolic activity, beginning in late 2012 and continuing through the end of March 2013. The restlessness spurred increased monitoring of the volcano.

Figure (see Caption) Figure 10. A map illustrating hazards at the Ampato-Sabancaya volcanic complex (high danger, red; moderate danger, orange; and low danger, yellow). Types of volcanic hazards include pyroclastic flows (including debris flows), mudflows, lava flows, and avalanches. The overall thickness of ash deposits from eruptions during 1990-1998 is indicated by 1 and 0.1 cm isopachs. Major roads and highways are shown as thick, dark red lines; thin lighter red lines are elevation contours. The map shown is featured on a poster with more details. From Mariño and others (2013).

Between 1988 and 1997, activity at Sabancaya was intermittent and characterized by low to moderate Vulcanian eruptions (VEI 2) and mainly modest eruption columns (less than 5 km above the summit) with local ashfall (e.g., SEAN 13:06; BGVN 19:03). After this eruptive episode, between 1998 and 2012, minor and intermittent fumarolic emissions rose from the active crater. During the last months of 2012, a slight increase of fumarolic activity was observed during a field campaign by Peru’s Instituto Geológico Minero y Metalúrgico (INGEMMET) volcanologists and their counterparts from the Laboratoire Magmas et Volcans (Clermont-Ferrand, France).

The Instituto Geofisico del Peru (IGP) reported that inhabitants from Sallalli hamlet, ~ 11 km S of Sabancaya, observed an increase in fumarolic emissions beginning 5 December 2012. Meteorological conditions prevented IGP scientists from visiting the area during the rainy season.

In mid-February 2013, local residents reported an increase in fumarolic activity, which was confirmed by INGEMMET scientists that visited the volcano on 15 and 22-23 February (figure 11). Scientists also reported a strong sulfur odor within an 8-km radius, and felt several strong earthquakes probably associated with the volcano’s unrest.

Figure (see Caption) Figure 11. Photograph taken of a gas plume above the active vent of Sabancaya, as seen from the SE flank on 17 February 2013. Courtesy of Pablo Samaniego, IRD.

IGP reported that within a span of 95 minutes on 22 February 2013, three earthquakes, of M 4.6, 5.2, and 5.0 respectively, were registered at Sabancaya (figure 12). This activity prompted IGP to install a network of close proximity seismic stations. Earthquakes continued through the following day (23 February) and caused damage at Maca village, 20 km NE of the crater.

Figure (see Caption) Figure 12. The principal earthquakes (red dots) registered at Sabancaya on 22 February 2013. Of these, three earthquakes of M 4.6, 5.2, and 5.0 occurred within a span of 95 minutes. Courtesy of IGP.

During 22-23 February, a seismic station installed by INGEMMET registered more than 500 small volcano tectonic (VT) seismic events at Sabancaya. On 23 February IGP separately reported 560 events at the Cajamarcana seismic station (CAJ on figure 13b) on the SE flank. According to a Reuters article from 27 February, 80 homes were damaged by the seismicity during 22-23 February, leading to some evacuations. During that seismicity, a plume rose ~100 m above Sabancaya. After 24 February, VT, long period (LP), and hybrid seismicity continued (figure 13).

Figure (see Caption) Figure 13. (a) Plot of daily earthquakes at Sabancaya, showing the number of volcano tectonic, long period, and hybrid events that occurred during 24 February-27 March 2013. (b) The locations of earthquake epicenters on 27 March 2013 (red dots) and the seismic stations that were monitoring the volcano as of that date (yellow triangles). Courtesy of IGP.

Reference. Mariño J., Samaniego P., Rivera M., Bellot N., Manrique N., Macedo L., Delgado R., 2013, Mapa de peligros del Complejo Volcánico Ampato-Sabancaya, Esc. 1:50.000. Edit. INGEMMET-IRD.

Information Contacts: Instituto Geológico Minero y Metalúrgico (INGEMMET), Av. Dolores (Urb. Las Begonias B-3), J.L. Bustamante y Rivero, Arequipa, Perú (URL: http://www.ingemmet.gob.pe); Pablo Samaniego Eguiguren, Laboratoire Magmas et Volcans, Université Blaise Pascal, Le Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD), Casilla 18-1209, Calle Teruel 357 - Miraflores, Lima 18 - PERU (URL: wwwobs.univ-bpclermont.fr/lmv/pperm/samaniego_p/index.php); Reuters, report by Lima Newsroom; Orlando Macedo, PhD, Chief of Volcanology Research Department, Instituto Geofisico del Peru, (IGP), Arequipa Volcano Observatory, Urb. La Marina B-19, Cayma, Arequipa, Peru.


May 2016 (BGVN 41:05) Citation IconCite this Report


Increased seismicity February 2013; explosive events in August 2014

Although historical records of eruptive activity at Peru's Sabancaya volcano go back to 1750, there have only been a handful of eruptions documented since the 1980s; activity that began in 1986 was the first recorded in over 200 years. Weak solfataric activity from vents within and outside the 350-m-wide summit crater since then has created a persistent risk of ash plumes, Vulcanian explosions, and glacial melting causing mudflows. Reports of fresh ashfall on snow-covered slopes in 2003 (BGVN 29:01) indicated that some level of eruptive activity was continuing into the early 2000's. An increase in seismic and fumarolic activity in late 2012 and 2013 led to increased monitoring at the volcano, located 72 km NW of Arequipa. IGP-OVS (Instituto Geofisico del Peru, Observatoria Vulcanologico del Sur) and OVI-INGEMMET (Observatorio Volcanologico del INGEMMET, Instituto Geológical Minero y Metalúrgico) installed a number of seismic stations after significant seismic events in February 2013 (reported on in BGVN 38:02) caused damage to numerous homes in the area.

While the data reported by Peru's IGP-OVS and OVI-INGEMMET indicate ongoing seismic activity beginning in February 2013, and two phreatic-type explosions on 9 and 25 August 2014, no substantial eruption of ash was reported between February 2013 and February 2016. Numerous VAAC (Volcanic Ash Advisory Center) reports of ash were reported by pilots, but the Buenos Aires VAAC noted that no ash plume was visible either on satellite images or from the web camera located near the volcano. Occasional references to "possible light volcanic ash" are mentioned in some VAAC reports, but generally not corroborated with visual or satellite information. A few photographs from the area appear to show trace amounts of fine ash or particulates from magmatic gases in the snow around the crater, but such deposits were not confirmed by fieldwork. Throughout the period, Sabancaya emitted significant water vapor plumes occasionally as high as 3,000 m, and SO2-rich magmatic gases that were blue in color and possibly contained trace amounts of ash.

Activity during 2013 and 2014. After a decade of quiet, a significant increase in fumarolic emissions was observed in late 2012 (BGVN 38:02). Throughout 2013 earthquakes were concentrated in areas NE, N and NW of the crater up to 25 km away; much of this seismicity was later interpreted by IGP-OVS to be related to regional tectonism and not to volcanic activity. An increase in SO2 emissions, seen as bluish gas emitting from the fumaroles, was observed in March 2013, but a field visit in May noted no fresh lava or ash in the area.

White, gray, and bluish SO2-rich fumarolic emissions increased in June 2014. VT (volcano-tectonic) earthquakes were recorded within 1.7 km of the crater in early July; IGP-OVS seismologists identified hybrid-type seismic events that they associated with the rise of magmatic material near the crater in early July. By mid-July, VT earthquakes were averaging over 200 per day, and the foci were located 12 km NNE of the crater. During late July, seismic events decreased, and the foci moved to 8 km N of the crater. Persistent off-white and bluish fumaroles rose 500-600 m above the crater during July 2014.

Fumarolic emissions intensified markedly on 5 August 2014, rising to 3 km above the crater; whitish water vapor, bluish magmatic gases, and gray emissions were observed, suggesting a "possible release of minor volcanic ash", as reported by IGP-OVS. The VT seismic events also began to increase in magnitude, ranging between 2.5 and 4.6 ML, including two located very close to the crater, between 4 and 14 km deep. Both LP and Hybrid seismic events, increased to hundreds of events per day in the early days of August. At 0429 local time on 9 August 2014 a large explosion was recorded; it was not observed due to darkness and cloud cover. After the explosions, VT events dropped back to tens per day, and emissions rose to between 500 and 1,000 m above the crater. Many of the earthquakes were located within 1.5 km of the crater at depths between 4 and 14 km. On 25 August beginning at 2039 local time four consecutive explosions lasting a total of 82 seconds were recorded (figure 14). Again, due to darkness, there was no visual confirmation of the explosion.

Figure (see Caption) Figure 14. Seismograph from 25 August 2014 at SAB seismic station, located 3 km from the top of Sabancaya. Four explosive events occurred in the crater area at 2039 local time, followed by numerous small earthquakes. The energy calculated by IGP-OVS for this sequence of events was 1,151 MJ, with a total duration of 82 seconds. Courtesy of IGP-OVS (2014 Annual Report, Sabancaya).

In the days between the 9 and 25 August explosions, observed emissions from the fumaroles were water vapor and bluish magmatic gases rising to heights between 500 and 1,500 m above the crater (figure 15).

Figure (see Caption) Figure 15. Emissions from Sabancaya on 13 August 2014. White vapor plumes and bluish SO2-rich magmatic gases are emitting from the crater. Courtesy of IGP-OVS (2014 Annual report, Sabancaya).

Water vapor and magmatic gas plume heights in September 2014 rose between 500 and 2,000 m above the crater. OVI-INGEMMET daily reports noted grayish plumes containing "possible ash" on 26 and 29 September 2014.

In October 2014, fumarolic emission heights were below 1 km above the crater; they were generally white steam plumes but also showed significant bluish SO2 content. Constant emissions of water vapor and SO2 to heights of 1,400 m above the floor of the crater continued into November along with intermittent seismic activity at constant levels since August. Seismicity increased slightly in early December and fumaroles of water vapor and SO2 were observed rising to heights between 500 and 1,600 m above the crater floor. Seismic signals characteristic of a mudflow were recorded in mid-December 2014 in the ravine between Sabancaya and Ampato, the large volcano immediately SW.

Buenos Aires VAAC reports in 2014 were all ambiguous as to the presence of ash from Sabancaya. A "faint ash cloud" was detected in visible imagery on 14 July 2014. Numerous pilot reports of ash between August and December were not verified by satellite imagery under clear skies, and the webcam usually revealed water vapor emissions or cloud cover at the summit at the time of most of the reports. VAAC reports that do mention "possible minor volcanic ash" were given on 16 September, 23 October, 10 November, and 27 December 2014.

Activity during 2015 and early 2016. A similar level of activity continued during 2015. Neither OVI-INGEMMET nor IGP-OVA reported explosions with ash emissions during the year. Constant emissions of steam and bluish magmatic gases were observed from the fumaroles within the crater. Plumes of water vapor and magmatic gases rose to 1 km above the crater in January and to 1.2 km in February. From March through May seismic activity remained steady and fumarolic plumes were consistently below 1 km above the crater.

Seismicity increased during June 2015. Fumarolic plume heights also increased to 2.4 km above the crater, and bluish SO2-rich gases were frequently observed. During July, some seismic events were located within 3 km of the crater, and fumarolic plumes rose to 2 km. Volcanologists from OVI-INGEMMET visited on 10 July 2015 and observed trace amounts of ashfall or particulates from SO2 emissions in the vicinity of the crater (figure 16). IGP-OVS scientists who visited in late July to make temperature measurements observed constant water vapor and magmatic gas emissions. The temperature at the side of the dome was measured at 81°C, and the hottest points at the bottom of the crater were 391° and 280°C.

Figure (see Caption) Figure 16. Crater inspection of Sabancaya on 10 July 2015 where trace amounts of ash or particulates from SO2 emissions were observed. Courtesy of OVI-INGEMMET.

During late August 2015 and the first week of September seismicity increased significantly, and was located within 6 km of the crater at depths between 6 and 9 km. Fumarolic emissions ranged between 600 and 1,600 m above the crater. Seismicity was low during October. An IGP-OVS visit on 1 October obtained temperature data similar to that collected in late July. The expedition reported the absence of recently deposited solid material in the vicinity of the crater, and also observed the constant emission of steam and magmatic gases (figure 17).

Figure (see Caption) Figure 17. Emissions of white steam and bluish magmatic gases from Sabancaya in the early hours of 1 October 2015. Courtesy of IGP-OVA (2015 Annual report, Sabancaya).

VT seismicity remained low in November 2015, but an increase in the second week in December included two events (4.0 and 3.6) located within 2 km of the volcano. Constant emissions of water vapor and magmatic gases rising to 1,100 m were observed.

Buenos Aires VAAC reports for 2015 were again ambiguous about the presence of ash. Many reports note that pilot observations of ash clouds were not corroborated by satellite or webcam images. However, on several occasions, the VAAC reports indicated that the webcam showed continuous emission of steam, gases, and "possible light volcanic ash" (8 March, 19 May, 15 and 21 June, 18 and 21 July, 26 August, 10 October, 6 November and 12 December).

Sabancaya maintained a similar level of seismic and fumarolic unrest through February 2016 that was monitored and reported by both OVI-INGEMMET and IGP-OVS. OVI-INGEMMET reported plume heights of water vapor in early January as high as 2,000 m above the crater, gradually decreasing to below 1,000 m in early February. The intermittent presence of magmatic gases was also noted during this time.

While there have not been substantial ash emissions since renewed seismic activity began in 2013, there have been measurable SO2 emissions observed by IGP-OVS and recorded by NASA's OMI instrument (figure 18). Emissions of SO2 recorded on 27 December 2014 (0.937 kT), 3 April 2015 (0.750 kt), 28 November 2015 (0.773 kt), 25 February 2016 (0.365 kt) appear most likely to have originated at Sabancaya.

Figure (see Caption) Figure 18. Four different images from the OMI instrument satellite data from NASA's Goddard Space Flight Center showing SO2 anomalies possibly attributable to Sabancaya (upper left triangle). The image dates are 27 December 2014 (top left), 3 April 2015 (top right), 28 November 2015 (bottom left), and 25 February 2016 (bottom right). Courtesy of NASA Goddard Space Flight Center.

Information Contacts: Instituto Geofisico del Peru, Observatoria Vulcanologico del Sur (IGP-OVS), Arequipa Regional Office, Urb La Marina B-19, Cayma, Arequipa, Peru (URL: http://ovs.igp.gob.pe/); Observatorio Volcanologico del INGEMMET, (Instituto Geológical Minero y Metalúrgico) (OVI-INGEMMET), Barrio Magisterial Nro. 2 B-16 Umacollo - Yanahuara Arequipa, (URL: http://ovi.ingemmet.gob.pe); 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); NASA Goddard Space Flight Center, Global Sulfur Dioxide Monitoring Page, Atmospheric Chemistry and Dynamics Laboratory, (URL: http://so2.gsfc.nasa.gov/index.html).


May 2017 (BGVN 42:05) Citation IconCite this Report


Eruption with continuing ash plumes began on 6 November 2016

Although historical records of eruptive activity at Peru's Sabancaya volcano go back to 1750, there have only been a handful documented since the 1980s; activity that began in 1986 was the first recorded in over 200 years. During the last period of substantial ash eruptions between 1990 and 1998 ashfall deposits up to 4 cm thick were reported 8 km E of the volcano. Evidence for minor ash-emitting events was reported in 2000 and 2003. Intermittent seismic unrest and fumarolic emissions characterized activity from late 2012 through 2015. Seismically detected explosions during August 2014 led to releases of SO2 gases and steam plumes, some as high as 2 km, along with possible minor volcanic ash. Possible minor volcanic ash emissions were also mentioned by Peruvian authorities and pilot reports between September and December2014 but there were no confirmed reports of ash emissions during this period. A crater inspection during 9-10 July 2015 found trace amounts of ash at the crater that contained crystals of plagioclase, biotite, and amphibole, along with fresh volcanic glass. These were interpreted by the volcanologists to represent minor ash emissions during recent weeks.

Unrest with steam plumes and variable seismicity continued during 2016 until 6 November when continuous ash-bearing explosions began. Activity during 2016 through February 2017 is covered in this report with information from the two Peruvian observatories that monitor the volcano: Instituto Geofisico del Peru - Observatoria Vulcanologico del Sur (IGP-OVS), and Observatorio Volcanologico del INGEMMET (Instituto Geológical Minero y Metalúrgico) (OVI-INGEMMET). Aviation reports and notices come from the Buenos Aires Volcanic Ash Advisory Center (VAAC), and satellite data is reported from several sources.

Sabancaya maintained a level of seismic and fumarolic unrest through most of 2016, similar to levels recorded in 2014 and 2015, with almost constant water-vapor and SO2 plumes rising from the crater. Additionally, tectonic (not volcanic) seismicity caused damage and fatalities in nearby villages. An explosion on 27 August 2016 did not produce ash, but new areas of fumarolic activity on the N flank were observed around this time. Hybrid seismic events related to the movement of magma, and SO2 emissions, increased noticeably during September and October 2016. An explosive eruption with numerous ash plumes began on 6 November 2016. Continuous ash emissions with plume heights exceeding 10 km altitude were recorded several times through February 2017. Thermal anomalies were first measured in satellite data in early November, along with numerous significant SO2 plumes.

Activity during January-October 2016. Heights of plumes consisting of water vapor and minor magmatic gases generally decreased during January 2016, from 1,800 m to less than 1,200 m by the month's end. Seismic activity was generally low in terms of both numbers of events and magnitude. The daily number of events ranged from 8 to 20, and the largest event, a M 4.0, was registered on 29 January.

Plume heights continued declining in February, from 1,000 m during the first week to 400-800 m by the end of the month. During March, April, and May the heights of steam and SO2 plumes ranged from 200 to 1,300 m above the crater, and values of SO2 flux ranged from 600 to 1,500 metric tons per day (t/d). These values increased only slightly in July and August; plumes rose 2,000 m above the crater rim and SO2 emissions were as high as 2,600 t/d.

Seismicity continued at low levels through late August. Three significant tectonic earthquakes in mid-August were not related to volcanic activity, but the earthquake 25 km NE of Sabancaya on the Ichupampa fault on 14 August caused at least four fatalities, and numerous aftershocks were recorded in the region. A spike in SO2 emissions at the volcano to 4,030 t/d occurred shortly after the earthquake.

On 27 August 2016 there was a hybrid-type seismic event that IGP-OVS interpreted as an explosion of 72 MJ (Megajoules) of energy. An official statement from the Scientific and Technical Committee for Risk Management (IGP-OVS, OVI-INGEMMET, and others) issued on 6 September noted that "dense gray gases reached 1,000 m above the crater and drifted E." However, no VAAC reports were issued, and ash was not mentioned in the OVI INGEMMET weekly report.

During the last two weeks of August, two large zones of new fumarolic activity were detected in satellite imagery. OVI visited the site on 25 August, and IGP-OVS visited on 1 September 2016. The scientists observed areas of increased fumarolic emissions outside of the crater on the NE and NW flanks of the volcano (figure 19). The first zone was located on the NW flank and extended from the vicinity of the crater down to 5,700 m elevation, while the second area was located on the NE flank at about 5,600 m. Both areas follow a NW-SE trend. The flux of SO2 increased to values greater than 4,000 t/d at the end of August.

Figure (see Caption) Figure 19. New areas of fumarolic activity at Sabancaya, August 2016. Top: Two large fumarolic areas photographed on 1 September 2016 that appeared on the flanks during late August. The main zone was located on the NW flank and extended from the vicinity of the crater down to 5,700 m elevation, while the second area was located on the NE flank at about 5,600 m. Courtesy of IGP-OVS (Sabancaya Report 27, 1 September 2016) Bottom: Google Earth image showing location of fumarolic fields. A, B, C, and D are part of the NW flank field and E is the NE flank field. Courtesy of OVI-INGEMMET (Special Report, 1 September 2016).

OVI-INGEMMET reported an increase in the total number of seismic events during September 2016, especially hybrid-type events, along with generally lower plume heights, but increased emissions of SO2. IGP-OVS noted a swarm of hybrid-type seismic events on 27 September distinct from the distal tectonic-related events of the previous month, and indicative of an increase in volcanic activity. IGP-OVS returned to Sabancaya on 28 September 2016 to gather temperature measurements at the new fumarole areas. A NW-SE trending belt on the NE side of the volcano had temperature readings between 71° and 91°C.

At the beginning of October, water vapor and SO2 gas plumes rose as high as 2,000 m above the crater, and the SO2 flux was over 3,000 t/d. Volcanic seismicity increased from 220 earthquakes per day during the first week to 470 during the second week. SO2 emissions continued to increase and by 22 October were at 7,173 t/d.

From 9 January through 3 November 2016 the Buenos Aires VAAC issued 52 reports with pilot observations of ash. The VAAC was unable to confirm the presence of ash in emissions and instead described only water vapor or magmatic gases recorded via the web camera. There were no MODIS thermal anomalies shown by the MODVOLC or MIROVA systems from January 2014 through October 2016.

Activity during November 2016-February 2017. OVI-INGEMMET reported an eruption beginning at 2040 local time on 6 November 2016 (0140 on 7 November UTC) that started with an explosion and was followed by the continuous emission of low volume ash that rose up to 1,500 m above the crater rim (about 7,500 m altitude) (figure 20).

Figure (see Caption) Figure 20. The beginning of the eruption at Sabancaya, in the province of Caylloma in Arequipa, on 6 November 2016. Courtesy OVI-INGEMMET (Sabancaya 2016 Weekly Report 45).

Several types of volcanic-related seismic events continued to increase in number and intensity during November and December. The eruption exhibited an average of 39 daily explosive events with ash plumes (figures 21, 22, and 23) between 7 November and 15 December. There were 63 explosions on 30 November, and between 5 and 11 December there were 328 explosions.

Figure (see Caption) Figure 21. Ash plume rising over 4,000 m above the summit (5, 967 m elevation) at Sabancaya, 24 November 2016. Courtesy OVI-OVS (2016 Sabancaya Joint OVI-OVS Weekly Report 2, 21-27 November).
Figure (see Caption) Figure 22. Plume heights and compositions at Sabancaya from 28 October through 27 November 2016. Ash emissions began on 6 November, and continued to increase in density and plume height throughout the month. White circles represent water vapor, light gray are ash, dark gray are abundant ash, blue are SO2 gas, and yellow are sulfur aerosols. Courtesy OVI-OVS (2016 Sabancaya Joint OVI-OVS Weekly Report 2, 21-27 November).
Figure (see Caption) Figure 23. NASA Earth Observatory images of ash plumes from Sabancaya on 16 and 19 November 2016. The bright area to the SW in the 16 November image is snow near the peak of Mount Ampato, which is covered with ash in the 19 November image. The 16 November image was acquired by a multispectral imager on the European Space Agency's Sentinel 2 spacecraft. The Operational Land Imager (OLI) on Landsat 8 captured the November 19 image. Courtesy of NASA Earth Observatory.

Ash emissions were continuous from the beginning of the eruption through mid-December, with heights up to 4.5 km (10.5 km altitude) above the crater, according to the Scientific-Technical Committee of government scientists monitoring the eruption. Ashfall several millimeters thick was recorded in areas as far as 40 km away. During the first weeks of the eruption ash fell mainly to the E and NE on the villages of Maca, Achoma, Yanque and Chivay (18-30 km NE). Later in December, ashfall was reported W and NW in the villages of Huambo (28 km W), Cabanaconde (22 km NW), and Pinchollo (18 km N). On 26 December, ashfall was again reported in the villages of Cabanaconde, Pinchollo, and Tapay (25 km NW) to the NW and N, and Lari and Madrigal (20 km NE), Maca, and areas of Achoma to the NE. The seismic energy released from tremors and explosive events continued to increase throughout November into December (figures 24 and 25).

Figure (see Caption) Figure 24. Seismic energy and types of seismic events at Sabancaya, 6 November-8 December 2016. HIB are hybrid-type seismic events, TRE are tremors, EXP are explosions. Black line represents cumulative energy in Megajoules (MJ). Y axis is daily seismic energy on the left and cumulative energy on the right. Stars represent the period of continuous explosions. Courtesy of OVI-OVS (2016 Sabancaya Joint OVI-OVS Weekly Report 4, 5-11 December).
Figure (see Caption) Figure 25. Web camera image of ash-and-steam plume at Sabancaya, 9 December 2016. Courtesy of OVI-OVS (2016 Sabancaya Joint OVI-OVS Weekly Report 4, 5-11 December).

Beginning on 21 December there was a notable increase in seismicity (mainly of hybrid events), in the number (up to 52 per day) and height of plumes, and ash emissions. These changes led the Scientific-Technical Committee to raise the Volcanic Warning Level from Yellow to Orange (2 to 3 on a 4-level scale) on 28 December, warning people to remain more than 12 km from the crater (figures 26 and 27). A small lahar affected the area of Pinchollo (18 km N) on 3 January 2017.

Figure (see Caption) Figure 26. Dense ash cloud at Sabancaya, 26 December 2016. Increasing intensity of seismicity and number of explosions led to an increase in the Volcano Warning Level on 28 December. Courtesy of OVI-OVS (Informe Especial No. 01-2017).
Figure (see Caption) Figure 27. Seismic energy released by Sabancaya between 5 December 2016 and 4 January 2017. Note increasing energy of the explosions in early January. Courtesy of OVI-OVS (Informe Especial No. 01-2017).

Seismicity remained high during January with long-period (LP), tremor, and hybrid-type events all continuing, and an average of 70-76 daily explosions. During the second week in January explosions peaked at an average of 84 per day. This number decreased during early February to around 20 per day but then rose back to over 40 by the end of the month. A significant number of hybrid seismic events occurred during the last week of February.

Gas-and-ash plumes rose to 4.5 km above the crater in early January, dropping back to 2-3 km for the rest of the month, before rising again to 3-4 km (9-10 km altitude) during February. In their Special Report in January 2017, the joint Scientific-Technical committee presented a map showing that ash dispersal had affected communities in nearly every direction 40 km from the summit (figure 28).

Figure (see Caption) Figure 28. Area affected by ashfall (in pink) from Sabancaya as of mid-January 2017. Courtesy of OVI-OVS (Informe Especial No. 01-2017).

Buenos Aires VAAC Reports, November 2016-February 2017. The Buenos Aires VAAC first noted minor amounts of volcanic ash in emissions visible from the volcano webcam on 7 November 2016 (UTC). Ash was not identified in satellite imagery until midday 8 November when it was reported at 7.6 km altitude (about 1.7 km above the summit). Observations of continuous emissions of steam and ash were reported daily, when not obscured by weather, from then through the end of February 2017. Plume heights were commonly 7.6-8.2 km altitude, about 1.7-2.3 km above the summit. Higher plumes were also recorded a number of times during this period, including 10.3 km altitude on 17 and 23 November. The plume was clearly visible in satellite imagery on 24 November, drifting SE at 10.9 km. Plumes on 3 December rose 10 km and drifted SW; they were partially hidden by weather clouds. Pulses of volcanic ash drifting over 35 km SE at 10.6 km altitude were visible on 11 and 12 December. For most of January 2017 the plumes were obscured by weather clouds, but were visible on 6 January at 9.1 km altitude. Higher plumes were more often recorded in February; they rose continuously over 10 km from 4 to 7 February. The highest plume during the period was on 26 February, at 11.9 km, drifting SW.

Thermal anomalies in satellite data. The MIROVA thermal anomaly plot of MODIS data provided independent satellite confirmation of the beginning of the eruption. The first thermal anomaly appeared on 2 November 2016, and values increased in frequency and intensity in the subsequent weeks. Energy values reached moderate levels in early February 2017 (figure 29). The first MODVOLC thermal alert pixel for Sabancaya appeared on 6 January 2017. There were seven MODVOLC alert pixels in January and six in February, suggesting a persistent source of heat during this time.

Figure (see Caption) Figure 29. Log Radiative Power values for Sabancaya between 13 March 2016 and 13 March 2017. The first MIROVA-identified thermal anomaly was on 2 November 2016, and values increased in frequency and intensity after that. Courtesy of MIROVA.

Sulfur dioxide data. Sulfur dioxide plumes from Sabancaya were captured numerous times by the OMI satellite instrument from NASA's Global Sulfur Dioxide Monitoring system between November 2016 and February 2017. They revealed significant SO2 plumes travelling in all directions away from the summit for distances up to 200 km (figure 30).

Figure (see Caption) Figure 30. SO2 plumes drifting in different directions up to 200 km from Sabancaya captured by the OMI instrument on the Aura satellite. Clockwise from top left: 7 November 2016, first day of ash eruption, plume drifting SW and S towards Arequipa; 16 November 2016, plume drifting NE toward Lake Titicaca; 25 December 2016, plume drifting WSW over the Pacific Ocean; 27 February 2017, large plume drifting S and W, corresponding to an 11.9-km-altitude ash plume reported by Buenos Aires VAAC on 26 February. Courtesy of NASA GSFC.

Information Contacts: Observatorio Volcanologico del INGEMMET, (Instituto Geológical Minero y Metalúrgico), Barrio Magisterial Nro. 2 B-16 Umacollo - Yanahuara Arequipa, (URL: http://ovi.ingemmet.gob.pe); Instituto Geofisico del Peru, Observatoria Vulcanologico del Sur (IGP-OVS), Arequipa Regional Office, Urb La Marina B-19, Cayma, Arequipa, Peru (URL: http://ovs.igp.gob.pe/); NASA Earth Observatory, EOS Project Science Office, NASA Goddard Space Flight Center, Goddard, Maryland, USA (URL: http://earthobservatory.nasa.gov/); 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/); Hawai'i Institute of Geophysics and Planetology (HIGP), MODVOLC Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://modis.higp.hawaii.edu/); NASA Goddard Space Flight Center (NASA/GSFC), Global Sulfur Dioxide Monitoring Page, Atmospheric Chemistry and Dynamics Laboratory, Goddard, Maryland, USA (URL: http://so2.gsfc.nasa.gov/index.html ).

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Eruptive History


There is data available for 14 Holocene eruptive periods.


Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
2016 Aug 27 2017 Jun 1 (continuing) Confirmed 3 Historical Observations
2015 Jul 9 ± 14 days 2015 Dec 12 Confirmed 1 Historical Observations
2014 Aug 13 2014 Oct 25 (?) Confirmed 1 Historical Observations
2003 Jul 30 ± 1 days Unknown Confirmed 2 Historical Observations
2000 Apr 16 (?) ± 15 days 2000 Oct 29 (in or after) Confirmed 2 Historical Observations
1990 May 28 1998 Sep 16 (?) ± 15 days Confirmed 3 Historical Observations
1988 Jun 22 1988 Oct 16 (?) ± 15 days Confirmed 1 Historical Observations
[ 1987 Aug 7 ] [ Unknown ] Uncertain 2  
1986 Dec 16 ± 15 days Unknown Confirmed 1 Historical Observations
1784 Jul Unknown Confirmed   Historical Observations
1750 Unknown Confirmed   Historical Observations
1350 ± 150 years Unknown Confirmed   Tephrochronology
3490 BCE ± 40 years Unknown Confirmed 0 Radiocarbon (uncorrected)
6600 BCE (?) Unknown Confirmed   Tephrochronology

Deformation History


There is data available for 6 deformation periods. Expand each entry for additional details.


Deformation during 2013 Nov 15 - 2014 May 10 [Variable (uplift / subsidence); Observed by InSAR]

Start Date: 2013 Nov 15 Stop Date: 2014 May 10 Direction: Variable (uplift / subsidence) Method: InSAR
Magnitude: Unknown Spatial Extent: Unknown Latitude: -16.000 Longitude: -72.000

Remarks: Post-seismic deformation from 17 July 2013 earthquake

(f) TerraSAR-X interferogram showing postseismic deformation.

From: Jay et al. 2015.


Reference List: Jay et al. 2015.

Full References:

Jay, J. A., Delgado, F. J., Torres, J. L., Pritchard, M. E., Macedo, O., and Aguilar, V., 2015. Deformation and seismicity near Sabancaya volcano, southern Peru, from 2002 to 2015.. Geophys. Res. Lett., 42, 2780Ð2788. doi: 10.1002/2015GL063589..

Deformation during 2013 Jul 17 - 2013 Nov 15 [Variable (uplift / subsidence); Observed by InSAR]

Start Date: 2013 Jul 17 Stop Date: 2013 Nov 15 Direction: Variable (uplift / subsidence) Method: InSAR
Magnitude: Unknown Spatial Extent: 4.00 km Latitude: -16.000 Longitude: -72.000

Remarks: Aftershocks from July 17 earthquake

(e) TerraSAR-X interferogram showing deformation related to aftershock activity following the 17 July earthquake

From: Jay et al. 2015.


Model Solutions

Model Solution Type Min Depth Max Depth Min Volume Change Max Volume Change Remarks Citation
Plane (fault) 1 Jay et al. 2015

Reference List: Jay et al. 2015.

Full References:

Jay, J. A., Delgado, F. J., Torres, J. L., Pritchard, M. E., Macedo, O., and Aguilar, V., 2015. Deformation and seismicity near Sabancaya volcano, southern Peru, from 2002 to 2015.. Geophys. Res. Lett., 42, 2780Ð2788. doi: 10.1002/2015GL063589..

Deformation during 2013 May 12 - 2013 Jul 17 [Variable (uplift / subsidence); Observed by InSAR]

Start Date: 2013 May 12 Stop Date: 2013 Jul 17 Direction: Variable (uplift / subsidence) Method: InSAR
Magnitude: 16.000 cm Spatial Extent: 20.00 km Latitude: -16.000 Longitude: -72.000

Remarks: Mw 5.9 earthquake on 17 July 2013 and aftershocks

(d) TerraSAR-X interferogram showing deformation related to the Mw 5.9 earthquake on 17 July 2013 and inset showing deformation related to another earthquake of smaller magnitude

From: Jay et al. 2015.


Model Solutions

Model Solution Type Min Depth Max Depth Min Volume Change Max Volume Change Remarks Citation
Plane (fault) 4 Jay et al. 2015

Reference List: Jay et al. 2015.

Full References:

Jay, J. A., Delgado, F. J., Torres, J. L., Pritchard, M. E., Macedo, O., and Aguilar, V., 2015. Deformation and seismicity near Sabancaya volcano, southern Peru, from 2002 to 2015.. Geophys. Res. Lett., 42, 2780Ð2788. doi: 10.1002/2015GL063589..

Deformation during 2012 Jan 14 - 2013 May 12 [Subsidence; Observed by InSAR]

Start Date: 2012 Jan 14 Stop Date: 2013 May 12 Direction: Subsidence Method: InSAR
Magnitude: 6.000 cm Spatial Extent: 8.00 km Latitude: -16.000 Longitude: -72.000

Remarks: Earthquake swarm 22-23 February 2013

(c) TerraSAR-X interferogram showing deformation related to the earthquake swarm in late February 2013

From: Jay et al. 2015.


Model Solutions

Model Solution Type Min Depth Max Depth Min Volume Change Max Volume Change Remarks Citation
Plane (fault) 4 Jay et al. 2015

Reference List: Jay et al. 2015.

Full References:

Jay, J. A., Delgado, F. J., Torres, J. L., Pritchard, M. E., Macedo, O., and Aguilar, V., 2015. Deformation and seismicity near Sabancaya volcano, southern Peru, from 2002 to 2015.. Geophys. Res. Lett., 42, 2780Ð2788. doi: 10.1002/2015GL063589..

Deformation during 2002 Dec 06 - 2003 Sep 12 [Subsidence; Observed by InSAR]

Start Date: 2002 Dec 06 Stop Date: 2003 Sep 12 Direction: Subsidence Method: InSAR
Magnitude: 5.000 cm Spatial Extent: 13.00 km Latitude: -16.000 Longitude: -72.000

Remarks: Mw 5.3 earthquake on 13 December 2002

(a) ERS interferogram from track 454 showing subsidence related to the Mw 5.3 earthquake on 13 December 2002

From: Jay et al. 2015.


Model Solutions

Model Solution Type Min Depth Max Depth Min Volume Change Max Volume Change Remarks Citation
Plane (fault) 12 Jay et al. 2015

Reference List: Jay et al. 2015.

Full References:

Jay, J. A., Delgado, F. J., Torres, J. L., Pritchard, M. E., Macedo, O., and Aguilar, V., 2015. Deformation and seismicity near Sabancaya volcano, southern Peru, from 2002 to 2015.. Geophys. Res. Lett., 42, 2780Ð2788. doi: 10.1002/2015GL063589..

Deformation during 1992 - 1997 [Uplift; Observed by InSAR]

Start Date: 1992 Stop Date: 1997 Direction: Uplift Method: InSAR
Magnitude: Unknown Spatial Extent: 50.00 km Latitude: -16.000 Longitude: -72.000

Remarks: Uplift centered on Hualca Hualca volcano

Hualca Hualca, Peru, time span June 1992?April 1996 (3.9 yr)

From: Pritchard and Simons 2002.


Model Solutions

Model Solution Type Min Depth Max Depth Min Volume Change Max Volume Change Remarks Citation
Point 11 13 15000000 30000000 Pritchard and Simons 2002

Reference List: Pritchard and Simons 2002; Pritchard and Simons 2004.

Full References:

Pritchard, M. E., and M. Simons, 2002. A satellite geodetic survey of large-scale deformation of volcanic centres in the central Andes. Nature, 418, 167-171, doi:10.1038/nature00872.

Pritchard, M. E., and M. Simons, 2004. Surveying volcanic arcs with satellite interferometry: The central Andes, Kamchatka, and beyond. GSA Today, 14(8), 4-9, doi:10.1130/1052-5173(2004)014<4:SVAWSR>2.0.CO.

Emission History


There is no Emissions History data available for Sabancaya.

Photo Gallery


Volcanoes of three ages can be seen in this aerial view across northern Perú. The eroded, 6093-m-high Solimana volcano (foreground) has not erupted since the Pleistocene, but has an active fumarole. It is located NW of the younger Coropuna volcano (upper right), which has produced major flank lava flows during the Holocene. The three-peaked Sabancaya volcanic complex (upper left) includes the historically active cone of Sabancaya proper, which is flanked on the left by Hualca Hualca volcano and on the right by Ampato volcano.

Photo by Norm Banks, 1988 (U.S. Geological Survey).
See title for photo information.
A dark-colored 15-km-wide apron of trachytic and dacitic lava flows surrounds 5967-m-high Sabancaya volcano. The prominent lava flow at the left extends more than 10 km down the SSE flank. Ampato volcano in the background forms the 6288-m high point of the Sabancaya volcanic complex. Amapato and Hualca Hualca volcano (out of view to the right) have also erupted during the Holocene, but only Sabancaya has erupted in historical time.

Photo by Norm Banks, 1988 (U.S. Geological Survey).
See title for photo information.
The Sabancaya volcanic complex consists of Sabancaya volcano proper (foreground), the older 6288-m-high Ampato volcano (background), and 6025-m Hualca Hualca volcano. Sabancaya, viewed here from the NE, is constructed on the saddle between the two older volcanoes. It is the youngest of the three Holocene volcanic centers and the only one to have erupted in historical time. An extensive 15-km-wide apron of trachytic and dacitic lava flows surrounds the 5967-m-high volcano. Records of historical eruptions date back to 1750.

Photo by Norm Banks, 1988 (U.S. Geological Survey).
See title for photo information.
An ash-bearing plume rises above Sabancaya volcano in this photo taken from the NE, possibly in October, 1988. Voluminous steam plumes, some with dark, basal "rooster-tails," were observed to have risen 0.5-1 km above the summit on June 22, 1988. The northern flank of Ampato volcano rises at the far right.

Photo by Minard Hall, 1988 (Escuela National Politecnica, Quito).
See title for photo information.
Winds deflect an eruption column from Sabancaya volcano to the NE on July 13, 1990. Residents living near the volcano reported an explosive eruption from Sabancaya that began on May 28, 1990. Initially, several explosions occurred per day, producing plumes to about 2 km height. Activity intensified on June 4, and by the 8th explosions occurred at intervals of 5-10 minutes and ashfall covered a radius of 20 km. More-or-less constant ash emission continued until 1998.

Photo by Guido Salas, 1990 (University of San Antonio, Arequipa).
See title for photo information.
An explosive eruption from Sabancaya volcano is viewed from the east on June 9, 1990. Explosive activity, which had begun on May 28, 1990, was continuing in 1995. Sabancaya volcano was constructed on the saddle between Ampato (left) and Hualca Hualca volcanoes. Ashfall from Sabancaya in 1991, which accumulated on Hualca Hualca, caused increased melting of glaciers that produced mudflows down the Majes river drainage north of the volcano.

Photo by Ch. Pattry, 1990 (courtesy of Alberto Parodi I.)
See title for photo information.
An ash-rich vulcanian eruption plume, viewed from the SE, rises above Sabancaya volcano in northern Perú on April 15, 1991. Strong vulcanian explosions were observed at intervals of 20-30 minutes during an April 13-19 visit to the volcano. The explosions lasted about a minute and produced 3-4 km high ash clouds. Explosive activity at Sabancaya began in May 1990 and was continuing in 1995.

Photo by Pierre Vetsch, 1991.
See title for photo information.
The Sabancaya volcanic complex, viewed here from the east, consists of 6288-m Ampato volcano (left), the eroded 6025-m-high Hualca Hualca volcano (right), and Sabancaya volcano proper (center), which was constructed on the saddle between the two older volcanoes. The two older centers have produced morphologically youthful lava flows, but 5967-m-high Sabancaya is the only center to have erupted in historical time.

Photo by Norm Banks, 1988 (U.S. Geological Survey).
See title for photo information.

Smithsonian Sample Collections Database


There are no samples for Sabancaya in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

Affiliated Sites