Bezymianny

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  • Country
  • Subregion Name
  • Primary Volcano Type
  • Last Known Eruption
  • 55.978°N
  • 160.587°E

  • 2882 m
    9453 ft

  • 300250
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

6 February-12 February 2013

KVERT reported that during 1-8 February seismic activity at Bezymianny was obscured by strong seismicity at Tolbachik. A viscous lava flow continued to effuse on the lava-dome flank, accompanied by gas-and-steam emissions. A thermal anomaly was detected in satellite imagery on 31 January and 1 February; cloud cover prevented views on the other days.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)



 Available Weekly Reports


2013: February
2012: February | March | August
2011: February | April | September | October
2010: February | April | May | June | September | December
2009: June | December
2008: July | August
2007: April | May | October | November
2006: May | December
2005: January | May | November | December
2004: January | June
2003: July | August
2002: January | November | December
2001: June | July | August | December
2000: November


6 February-12 February 2013

KVERT reported that during 1-8 February seismic activity at Bezymianny was obscured by strong seismicity at Tolbachik. A viscous lava flow continued to effuse on the lava-dome flank, accompanied by gas-and-steam emissions. A thermal anomaly was detected in satellite imagery on 31 January and 1 February; cloud cover prevented views on the other days.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


29 August-4 September 2012

KVERT reported that seismic activity at Bezymianny had increased in the middle of August. During 24-31 August levels were moderate; 17 events were recorded on 28 August and 71 events were recorded on 31 August. Observers noted weak-to-moderate fumarolic activity during 25-26 and 29 August; cloud cover prevented observations on the other days. A thermal anomaly was detected in satellite imagery on 25 August.

Based on seismic data analyses, an explosive eruption occurred from 0716 to 0745 on 2 September. Ash plumes rose to altitudes of 10-12 km (32,800-39,400 ft) a.s.l. and drifted more than 1,500 km ENE. A thermal anomaly observed in satellite imagery was very bright before the explosion. The Aviation Color Code was raised to Orange, then Red. Ash plumes rose to an altitude of 4 km (13,100 ft) a.s.l. and drifted NE later that day, then ash emissions ceased. Ash plumes continued to be detected in satellite imagery and drifted 450-600 km ENE and SE. The Aviation Color Code was lowered to Yellow. On 3 September seismic activity was low. A viscous lava flow effused on the lava-dome flank, and was accompanied by fumarolic activity and hot avalanches.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


7 March-13 March 2012

KVERT reported that a strong explosive eruption from Bezymianny was detected by seismic instruments on 9 March. Ash plumes rose to altitudes of 3.5-5 km (11,500-16,400 ft) a.s.l. and drifted NE. During the most intense phase of the eruption ash plumes from pyroclastic flows rose to an altitude of 8 km (26,200 ft) a.s.l. Satellite imagery showed the plume drifting 700 km NE. Ashfall was reported in Ust-Kamchatsk Village (120 km ENE). Later that day activity decreased significantly and the Aviation Color Code was lowered to Orange. During 9-13 March strong gas-and-steam emissions were noted, a viscous lava flow effused onto the lava-dome flank, and a thermal anomaly continued to be detected in satellite imagery. The Aviation Color Code was lowered to Orange on 14 March.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


29 February-6 March 2012

KVERT reported that during 24 February-2 March seismic activity at Bezymianny remained elevated, with about 7-19 weak events registered daily. A thermal anomaly was detected in satellite images. Gas-and-steam activity was observed on 26 February; clouds obscured the volcano on the other days. One short volcanic tremor episode was detected on 29 February. About 40 seismic events were detected on 1 March and, according to satellite data analysis, the size and brightness of a thermal anomaly abruptly increased on 2 March. The Aviation Color Code was raised to Red. During 2-5 March there were 25-40 weak seismic events detected; cloud cover prevented observations of the volcano.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


22 February-28 February 2012

KVERT reported high levels of seismic activity at Bezymianny during 17-24 February and a thermal anomaly that was detected daily in satellite images. Two short volcanic tremor episodes were reported on 15 and 22 February. Gas-and-steam plumes, observed in satellite images, drifted NE on 20 and 22 February. The Aviation Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


15 February-21 February 2012

KVERT reported that seismic activity increased at Bezymianny on 12 February and remained elevated through 19 February. The size and brightness of a thermal anomaly observed in satellite images both increased during this interval. Blocks possibly extruded from the top of the lava dome. KVERT raised the Aviation Color Code to Orange on 19 February.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


26 October-1 November 2011

KVERT reported that during 21-28 October seismic activity at Bezymianny was low. A thermal anomaly was observed in satellite imagery during 23-25 October, and fumarolic activity was observed during 23 and 25-26 October. The Aviation Color Code remained at Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


14 September-20 September 2011

KVERT reported that during 9-15 September seismic activity at Bezymianny was low. An observer in the area on 6 September noted that lava continued to effuse on the SSE flank. The Aviation Color Code remained at Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


27 April-3 May 2011

KVERT reported that during 22-29 April a bright thermal anomaly on Bezymianny was detected in satellite imagery. A gas-and-steam plume that drifted 27 km NW was also detected on 22 April. According to ground-based observations, gas-and-steam activity was noted during 22 and 24-25 April. The Aviation Color Code was lowered to Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


20 April-26 April 2011

In addition to producing ashfall 45 km to the NNW on 14 April, KVERT reported that the explosive eruption from Bezymianny also generated a viscous lava flow on the SE flank. Incandescence from the lava flow was visible on 19 April. Satellite imagery showed a thermal anomaly during 15-22 April, and small ash-and-gas plumes on 16 April. The Aviation Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


13 April-19 April 2011

KVERT reported that seismic data suggesting a strong explosive eruption from Bezymianny began at 0820 on 14 April and lasted for 40 minutes. The Aviation Color Code level was raised to Red. Ash fell in Krasny Yar (45 km to the NNW). Cloud cover prevented observations. No activity was observed in satellite imagery; ash plumes may have been below meteorological clouds observed around 8 km a.s.l. The Aviation Color Code level was lowered to orange the next day.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


6 April-12 April 2011

KVERT reported that during 1-11 April seismicity from Bezymianny increased. Gas-and-steam activity was observed during 1-2 April; clouds obscured views on the other days. A thermal anomaly over the volcano observed in satellite imagery was weak during 1-3 and 6 April, then increased in size and became more intense. The Aviation Color Code was raised to Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


2 February-8 February 2011

KVERT reported that during 28 January-4 February seismicity from Bezymianny did not exceed background levels, however weak volcanic earthquakes were detected. A thermal anomaly over the volcano was observed daily in satellite imagery. Gas and steam activity was observed during 30-31 January and 1-3 February; cloud cover prevented observations on the other days. The Aviation Color Code level remained at Yellow.

Based on information from the Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 4 February an ash plume rose to an altitude of 4.6 km (15,000 ft) a.s.l. drifted NE.

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)


29 December-4 January 2011

KVERT reported that during 24-30 December seismicity did not exceed background levels. The temperature of thermal anomalies observed in satellite imagery during 23-24 and 27-28 December gradually increased. Gas-and-steam emissions were seen on 27 and 28 December; clouds prevented observations on the other days. The Aviation Color Code level remained at Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


8 December-14 December 2010

KVERT reported that, based on air photos taken of Bezymianny by helicopter on 21 November, a new area of lava possibly had extruded from the top of the lava dome. During 3-10 December seismicity did not exceed background levels. On 3 and 7 December gas-and-steam emissions were seen, the same days a weak thermal anomaly was detected in satellite imagery. The Aviation Color Code level remained at Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


1 September-7 September 2010

KVERT reported that a thermal anomaly over Bezymianny was observed in satellite imagery on 29 August and 1 September. Gas-and-steam activity was also noted on 1 September. Cloud cover prevented observations of the volcano on the other days during 27 August-3 September. The Aviation Color Code level remained at Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


9 June-15 June 2010

KVERT reported that although clouds prevented views of Bezymianny during 4-11 June, thermal anomalies were seen in satellite imagery during 4-5 and 8 June. The Aviation Color Code level remained at Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


2 June-8 June 2010

KVERT reported that after an explosive eruption from Bezymianny on 1 June two bright thermal anomalies on the flanks were seen in satellite imagery during 1-2 June, possibly from pyroclastic flow deposits. On 4 June KVERT noted that strong gas-and-steam emissions continued to rise from the lava dome. The Aviation Color Code level was lowered to Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


26 May-1 June 2010

KVERT reported that some earthquakes were detected in the vicinity of Bezymianny's lava dome during 23-24 May, even though much of the seismicity was obscured by strong activity from Kliuchevskoi. Fumarolic activity was seen on 21 May. The temperature of the thermal anomaly detected in satellite imagery increased from 18 degrees Celsius on 19 May to 48.8 degrees Celsius on 23 May. The Aviation Color Code level was raised to Orange. During 21-28 May satellite data showed a variable but daily thermal anomaly over the lava dome. Fumarolic activity was occasionally detected, and another seismic event was recorded on 24 May.

Seismic data indicated that an explosive eruption began on 1 June, producing a large ash cloud about 127 by 93 km in dimension. The Aviation Color Code level was raised to Red. Further analyses showed that ash plumes from two explosions rose to altitudes of 8-10 km (26,200-32,800 ft) a.s.l. and drifted at first 250 km W and then 160 km N and NE. Ashfall was reported in Kozyrevsk village, 45 km W. Two bright thermal anomalies were seen in satellite imagery, possibly from pyroclastic flow deposits. The next day, strong gas-and-steam emissions rose from the lava dome. The Aviation Color Code level was lowered to Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


14 April-20 April 2010

KVERT reported that during clear weather at Bezymianny during 8-13 April moderate fumarolic activity was observed and satellite data showed a weak thermal anomaly over the lava dome. The Aviation Color Code level remained at Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


10 February-16 February 2010

KVERT reported that during 5-12 February a thermal anomaly from Bezymianny's lava dome was detected in satellite imagery. On 6 February a new hot lava flow from the lava dome was observed. Fumarolic activity was observed on 7 and 9 February. The Aviation Color Code level was lowered to Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


3 February-9 February 2010

KVERT reported that during 29-30 January and 2 February a thermal anomaly from Bezymianny's lava dome was detected in satellite imagery. The anomaly was larger during 7-8 February, prompting KVERT to raise the Level of Aviation Color Code to Orange. Strong activity from Kliuchevskoi volcano had obscured seismic signals from Bezymianny since 4 January.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


23 December-29 December 2009

KVERT reported that during 21-23 December a large and intense thermal anomaly from Bezymianny was detected in satellite imagery. During 22-24 December seismic activity was elevated and fumarolic activity was observed. Gas-and-steam plumes rose to an altitude of 4 km (13,100 ft) a.s.l. The Level of Aviation Color Code remained at Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


16 December-22 December 2009

KVERT reported that seismic activity from Bezymianny increased on 8 December. After a significant thermal anomaly was detected in satellite imagery on 17 December, the Level of Aviation Color Code was raised to Red. A few hours later a large explosive eruption produced ash plumes that were seen drifting as far as 350 km W and NW in satellite imagery. Ash plumes likely rose to altitudes greater than 10 km (32,800 ft) a.s.l.; clouds in the area prevented visual observations. Ashfall up to 3 mm thick was noted in Kozyrevsk, 45 km W, and other surrounding villages. The Level of Aviation Color Code was lowered to Orange after seismic activity significantly decreased. On 18 December another large thermal anomaly was seen over the volcano and on the SE flank. Gas-and-steam activity was also noted. During 19-20 December, a thermal anomaly continued to be detected in satellite imagery. KVERT lowered the Level of Aviation Color Code to Yellow on 21 December.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


17 June-23 June 2009

Reports from KVERT since August 2008 have indicated continuing dome growth and weak fumarolic activity at Bezymianny, with thermal anomalies visible in satellite data when the volcano was visible. Over the previous month such anomalies were seen on 21 and 30 May, and 2-4, 7, and 11-14 June.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


20 August-26 August 2008

KVERT reported that seismic activity at Bezymianny was slightly above background levels during 14 and 16-18 August and at background levels during 15 and 20-21 August. Analysis of satellite imagery revealed a thermal anomaly over the lava dome during 14-15 and 18-21 August. The thermal anomaly enlarged just before an explosion on 19 August. The explosion produced an ash plume that rose to an altitude of 9 km (29,500 ft) a.s.l. and drifted 1,200 km W. Staff at a seismic station about 50 km W reported ashfall and the smell of volcanic gas. The Level of Concern Color Code was lowered to Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


13 August-19 August 2008

Based on observations of satellite imagery, KVERT reported that a thermal anomaly detected over Bezymianny's lava dome was strong during 9-14 August. Seismic activity was slightly above background levels during 10-14 August, possibly indicating that hot avalanches occurred. The Level of Concern Color Code remained at Orange.

Based on observations of satellite imagery and information from KEMSD, the Tokyo VAAC reported that on 19 August, an eruption plume rose to an altitude of 7.9 km (26,000 ft) a.s.l. and drifted W.

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)


6 August-12 August 2008

Based on observations of satellite imagery, KVERT reported that a thermal anomaly detected over Bezymianny's lava dome grew in area and intensified during 9-11 August. Based on interpretations of seismic data, four hot avalanches occurred on 10 August and nine occurred on 11 August. On 12 August, the level of Concern Color Code was raised to Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


23 July-29 July 2008

KVERT reported that seismic activity at Bezymianny was above background levels on 20 July and at background levels the other days during 18-25 July. Fumarolic activity was observed during 18-22 July and area volcanologists reported that the lava dome continued to grow. Weak thermal anomalies over the lava dome were detected in satellite imagery on 18, 19, and 20 July. KVERT lowered the level of Concern Color Code to Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


16 July-22 July 2008

KVERT reported that intermittent volcanic tremor at Bezymianny was detected on 11 July and seismic activity was above background levels during 11-16 July. Weak thermal anomalies over the lava dome were detected in satellite imagery on 11 and 15 July. Hot avalanches were reported by local observers on 15 July. The level of Concern Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


9 July-15 July 2008

Increased seismicity at Bezymianny was reported by KVERT on 12 July 2008, when the Level of Concern Color Code was raised to Orange. Intermittent volcanic tremor was recorded on 11 July, along with observations of hot avalanches and strong fumarolic activity. Weak thermal anomalies were detected in satellite imagery.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


28 November-4 December 2007

Based on reports from KVERT, the Washington VAAC reported an ash plume from Bezymianny at an altitude of 4.3 km (14,000 ft) a.s.l. on 2 December. Ash was not identified on satellite imagery. The level of Concern Color Code remained at Yellow.

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Washington Volcanic Ash Advisory Center (VAAC)


7 November-13 November 2007

KVERT reported that possibly high-temperature gas-and-steam plumes from Bezymianny along with a thermal anomaly at the summit were visible on satellite imagery on 9 November. A viscous lava flow effused from the summit. During an overflight on the same day, 4-km-long pyroclastic flow deposits from 5 November were observed on the SE flank. Lava flow-front collapses from older lava flows on the SE flank were also evident. The level of Concern Color Code was raised to Orange on 10 November.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


31 October-6 November 2007

Based on seismic interpretation, KVERT reported that a series of explosions or collapses from lava flow fronts at Bezymianny occurred on 5 November. Two avalanches and an ash plume were also detected. Observations of satellite imagery revealed a thermal anomaly over the lava dome. The level of Concern Color Code remained at Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


17 October-23 October 2007

KVERT reported that seismic activity at Bezymianny was slightly elevated during 16-19 October and returned to background levels during 19-20 October. Based on observations of satellite imagery, a strip of ash deposits was noted on the ESE flank on 18 October and a thermal anomaly was present in the crater during 16-20 October. On 20 October, KVERT lowered the level of Concern Color Code to Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


10 October-16 October 2007

During 5-12 October, KVERT reported that seismic activity at Bezymianny was at background levels. Based on observations of satellite imagery, a thermal anomaly was present in the crater on 4, 6, 8, and 11 October. Fumarolic activity was observed during 6-7 and 10-11 October. Based on seismic interpretation, a hot avalanche probably occurred on 10 October.

Based on observations of satellite imagery and seismic interpretation, a small eruption occurred on 15 October. Ash plumes drifted SE and a strong thermal anomaly was present in the crater. Based on information from KEMSD and observations of satellite imagery, the Tokyo VAAC reported that an ash plume rose to altitudes of 7.3-9.1 km (24,000-30,000 ft) a.s.l. and drifted E and SE. The level of Concern Color Code was raised from Yellow to Red.

No ash plumes were present on 16 October, and seismicity was only slightly above background levels. The level of Concern Color Code was lowered to Orange.

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)


16 May-22 May 2007

KVERT reported on 17 May that the Level of Concern Color Code for Bezymianny was lowered to Yellow. Satellite imagery showed that the thermal anomaly decreased in size during 15-17 May. Hunters reported that a large mudflow, 200 m in width, moved along the Sukhaya Khapitsa river on 17 May.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


9 May-15 May 2007

KVERT reported on 11 May that the level of Concern Color Code for Bezymianny was raised to Orange due to a large thermal anomaly noted on satellite imagery. During 0330-0400 on 12 May, an explosive eruption may have occurred according to seismic data from Kozyrevsk. Ash plumes were visible on satellite imagery drifting multiple directions. Ashfall was reported from the town of Klyuchi, about 47 km NE. A slight amount of the ash originated from Kliuchevskoi, an active volcano directly N of Bezymianny. Hot avalanches were observed and an ash plume rose to an altitude of 4 km (13,100 ft) a.s.l. On 13 May, an elongated thermal anomaly was seen on satellite imagery to the SE of the lava dome.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


25 April-1 May 2007

Based on [a pilot report to the] Petropavlovsk-Kamchatsky Flight Information Region (FIR) [at 0725], the Tokyo VAAC reported that on 29 April an ash plume from Bezymianny rose to an altitude of 6.1 km (20,000 ft) a.s.l. and drifted W. [Ash was not seen in MTSAT-IR satellite data about 26 minutes prior to the pilot report.]

[Later information regarding this reported event provided by KVERT noted that no satellite data reviewed by volcanologists contained ash plumes, there were no strong seismic events, and no explosions were seen on the video camera. Meteorological clouds were present at 4.5-5.0 km altitude overnight and through 0900 local time. No ash fell in the village of Kozyrevsk, which would have been expected had an ash plume drifted W.]

Sources: Tokyo Volcanic Ash Advisory Center (VAAC), Kamchatkan Volcanic Eruption Response Team (KVERT)


27 December-2 January 2007

Based on aerial observations, KVERT reported on 29 December that part of Bezymianny's lava dome was destroyed during explosive activity on 24 December. Moderate fumarolic activity was observed during 26-27 December and seismic activity was at background levels during 26-29 December. The level of Concern Color Code was lowered to Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


20 December-26 December 2006

The level of Concern Color Code for Bezymianny was raised from Yellow to Orange on 24 December due to an increase in incandescent avalanches, seismicity, and the intensity of a thermal anomaly at the summit. Within a few hours, a series of ash explosions and "ash avalanches" produced plumes that rose to altitudes of 6-10 km (19,700-32,800 ft) a.s.l. and drifted NE. The level of Concern Color Code was raised to Red. On 25 December, KVERT reported that seismic activity returned to background levels and explosive activity ceased. The level of Concern Color Code was returned to Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


10 May-16 May 2006

Following an explosive eruption at Bezymianny on 9 May, seismicity was at background levels on 10 May. In addition, fumarolic plumes were observed and lava flows probably extended from the lava dome. On 11 May the Concern Color Code at Bezymianny was reduced from Orange to Yellow. On 12 May, seismicity remained at background levels and gas-and-steam plumes were visible.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


3 May-9 May 2006

During 28 April to 5 May, Bezymianny's lava dome continued to grow. Seismicity was above background levels during 30 April to 3 May. Incandescent avalanches were visible on 4 May. At the lava dome, fumarolic activity occurred and thermal anomalies were visible on satellite imagery. Bezymianny was at Concern Color Code Yellow, which meant an explosive eruption was possible in the following 4 weeks. On 7 May the Concern Color Code was raised to Orange due to an increase in seismicity and the number of incandescent avalanches (14 occurred on 6 May in comparison to 4-6 during the previous 2 days). Intense fumarolic activity occurred, with occasional small amounts of ash. KVERT reported that an explosive eruption was possible in the next 1 or 2 weeks. On 9 May around 1935, the Concern Color Code was raised to Red, the highest level, due to increased seismicity and incandescent avalanches. A gas plume rose higher than 7 km (23,000 ft) a.s.l. and a strong thermal anomaly was visible on satellite imagery. An explosive eruption was expected in the next 1 or 2 days.

An explosive eruption occurred at Bezymianny on 9 May during 2121 to 2145. The explosion produced an ash column that rose to a height of ~15 km (49,200 ft) a.s.l. A co-ignimbrite ash plume was about 40 km in diameter and mainly extended NE of the volcano. On 10 May around 0100, seismicity returned to background levels and the Concern Color Code was reduced to Orange. Small fumarolic plumes were observed during the early morning of the 10th and lava probably began to flow at the lava dome.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


7 December-13 December 2005

After an explosive eruption at Bezymianny on 30 November, seismic activity at the volcano decreased to background levels. On 2 December the Concern Color Code was reduced from Orange to Yellow. On 9 December, KVERT reported that based on past experience with Bezymianny, a viscous lava flow was probably active at the summit lava dome and there were no indications that an explosive eruption was imminent.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


30 November-6 December 2005

Seismic data indicated an explosive eruption at Bezymianny on 30 November. Ash plumes were subsequently seen in satellite imagery extending SW at an altitude of about 6 km (19,700 ft) a.s.l. The Concern Color Code was raised to Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


11 May-17 May 2005

Weak gas-and-steam plumes were observed on 6-7 May, but clouds frequently obscure the volcano. A thermal anomaly at the dome was detected in satellite imagery on 6-8, 10, and 12 May. Bezymianny remained at Concern Color Code Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


12 January-18 January 2005

KVERT lowered the Concern Color Code at Bezymianny from Red (the highest level) to Orange on 12 January when seismic activity returned to background levels following the eruption of 11 January. As seismicity remained at background levels, the Concern Color Code was lowered on 14 January from Orange to Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


5 January-11 January 2005

KVERT raised the Concern Color Code at Bezymianny from Yellow to Orange on 7 January as seismicity at the volcano increased. On 11 January, the Concern Color Code was raised from Orange to Red (the highest level). According to seismic data, an explosive eruption of the volcano began at 2002 on 11 January and was inferred to have produced an ash column to 8-10 km a.s.l. No visual or satellite data were available as dense clouds obscured the volcano. Seismic activity was above background levels during the past week and increased continuously. About 60 earthquakes of magnitude 1.25-2.25, and numerous weaker, shallow events registered during 7-11 January. Intermittent volcanic tremor was recorded on 10 January.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


23 June-29 June 2004

An eruption at Bezymianny produced an ash cloud that during 18-19 June extended more than 1,000 km E and SE from the volcano and possible ash deposits extended 190 km SE from the lava dome. Seismicity at Bezymianny did not exceed background levels during 20-23 June. The Concern Color Code at Bezymianny was reduced from Orange to Yellow around 25 June.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


16 June-22 June 2004

According to KVERT, an eruption at Bezymianny on 19 June led them to raise the Concern Color Code to Red, the highest level. Activity first began to increase during 11-14 June, when seismicity was above background levels with 2-3 shallow earthquakes daily. On 16 June KVERT raised the Concern Color Code from Yellow to Orange. Then, on 19 June, seismic data were interpreted to indicate that explosive activity during 0840-0930 may have produced an ash plume to 8-10 km a.s.l. Video observations later confirmed the plume height. Satellite imagery showed that the plume extended about 200 km by 1319. Later that day, seismicity decreased and the Concern Color Code was reduced to Orange.

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Anchorage Volcanic Ash Advisory Center (VAAC), Tokyo Volcanic Ash Advisory Center (VAAC)


21 January-27 January 2004

During 16-23 January, following an eruption on the 14th, a lava dome continued to grow at Bezymianny, with viscous lava probably flowing from it. Precise seismic monitoring was hampered due to high-level volcanic tremor at nearby Kliuchevskoi volcano. On 22 January a gas-and-steam plume rose 3.5 km a.s.l. and extended NE. Bezymianny remained at Concern Color Code Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


14 January-20 January 2004

Video footage showed a strong explosion at Bezymianny on 14 January at 1053 producing an ash plume that rose to 6-8 km a.s.l. and extended ENE. A large pyroclastic flow probably traveled SSE down the volcano's flank. This abrupt increase in activity at Bezymianny led KVERT to raise the Concern Color Code from Green (the lowest level) to Red (the highest level), but later the same day they reduced it to Orange. By 1134 on 14 January the ash plume extended ~55 km and was at a height around 6 km a.s.l, and by 1421 it extended ~190 km and was at 4-6 km a.s.l. No ash was deposited in the nearby settlement of Ust'-Kamchatsk. On 16 January the Concern Color Code was further reduced to Yellow. On that day a lava dome was growing and viscous lava was probably flowing slowly from it. Precise seismic monitoring at Bezymianny was hampered due to high-level volcanic tremor at nearby Kliuchevskoi volcano. Visual observations at Bezymianny revealed that gas-and-steam plumes rose to ~100 m above the lava dome.

Prior to the 14 January eruption, a weak thermal anomaly has been registered at Bezymianny since an eruption on 26 July 2003. On 9 January one shallow M 2.2 earthquake was recorded at the volcano. During 10-13 January, a 1-2 pixel thermal anomaly was noted at the volcano and during 10-12 January gas-and-steam plumes rose to low levels above the volcano.

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC), Anchorage Volcanic Ash Advisory Center (VAAC), Pravda News


6 August-12 August 2003

No seismicity was recorded at Bezymianny during 31 July to 3 August, so KVERT reduced the Concern Color Code from Yellow to Green, the lowest level. On 2 August gas-and-steam plumes extended ~15 km NW of the volcano. A thermal anomaly was seen on satellite imagery on 1 August.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


30 July-5 August 2003

During 27-30 July, no seismicity was recorded at Bezymianny and visual observations were not possible due to meteorological clouds obscuring the volcano. A thermal anomaly was visible on satellite imagery on 28, 29, and 31 July, and 1 August. The Concern Color Code remained at Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


23 July-29 July 2003

A large explosion at Bezymianny on 26 July at 2220 produced an ash plume that rose to a height of ~8 km a.s.l. and drifted W. KVERT raised the Concern Color Code from Green to Red, the highest level. Prior to the eruption, a weak thermal anomaly was detected on satellite imagery on 6 July, and two shallow low-magnitude earthquakes were recorded on 23 and 25 July. On the 25th and 26th a several-pixel-large thermal anomaly and a gas-and-ash plume were seen on satellite imagery. On the 26th the active phase of the eruption lasted for ~4 hours. According to Yelizovo Airport Meteorological Center (AMC) and a pilot's report, by 26 July at 2226 the ash cloud was around 10-11 km a.s.l. On 27 July an ash cloud was visible 250-300 km W of the volcano and probable pyroclastic-flow deposits were seen on the volcano's SE flank. The same day the Concern Color Code was reduced from Red to Orange. No seismicity was recorded during 27-28 July and no visual information was available because Bezymianny was obscured by clouds. No new signs of eruptive activity were visible on satellite imagery after 26 July. On 29 July the Concern Color Code was further reduced from Orange to Yellow.

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC), Pravda News


31 December-6 January 2003

The Concern Color Code at Bezymianny was reduced from Yellow to Green on 3 January. Seismicity was not recorded during 28 December to 3 January. A weak thermal anomaly was seen on satellite imagery, which may be indicative of viscous lava on the lava dome.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


24 December-30 December 2002

A large explosive eruption occurred at Bezymianny on 25 December. Prior to the eruption, on 23 December, a 1-pixel-large thermal anomaly was detected on satellite imagery that increased to 7-10 pixels on 24-25 December. Seismicity was also slightly above background levels during 24-25 December, and weak intermittent spasmodic tremor was registered on the 25th. That same day at 1321 a very hot plume that probably contained ash was visible on satellite imagery. At this time the Concern Color Code was raised from Yellow to Orange. Moderate explosive activity began on the 25th around 1900. Seismic data revealed that a large explosive eruption occurred on 26 December at 0715. The resultant ash cloud rose 5 km a.s.l. and deposited ash in Kozyrevsk, 55 km NW of Bezymianny. The Concern Color Code was raised to Red.

The eruption continued through the 27th, but activity decreased. Three weak earthquakes were registered on the 26th, and the amplitude of intermittent spasmodic volcanic tremor gradually decreased. KVERT reported that a viscous lava flow was probably being emitted from the volcano's active lava dome. The Concern Color Code was reduced to Orange. On 28 December seismicity was at background levels. Meteorological clouds obscured views of the volcano during 27-28 December. On the 28th the Concern Color Code was reduced to Yellow.

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC), Interfax News


20 November-26 November 2002

The Concern Color Code at Bezymianny was reduced from Yellow to Green during 15-22 November. No seismic activity was recorded and satellite images revealed only a very weak thermal anomaly. KVERT stated that this hot spot may indicate hot gas emission from the lava dome.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


13 November-19 November 2002

KVERT raised the Concern Color Code at Bezymianny from Green to Yellow on 18 November. A one-pixel thermal anomaly was observed on various satellite imagery on both 16 and 17 November. The closest telemetered seismic stations, located on Kliuchevskoi volcano 13.5 km from Bezymianny's lava dome, only recorded several shallow seismic events at Bezymianny; 13 per month in August and September, and 3 in October. High seismic activity at Kliuchevskoi makes it difficult to distinguish Bezymianny's seismic events.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


2 January-8 January 2002

During 28 December- 4 January the Color Concern Code at Bezymianny was reduced from Yellow ("volcano is restless") to Green ("volcano is dormant"). During the report period seismicity was at background levels, small gas-and-steam plumes were produced, weak fumarolic activity occurred, and a faint thermal anomaly was visible on satellite imagery.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


26 December-1 January 2002

A reduction in volcanic and seismic activity during 21-28 December at Bezymianny led KVERT to reduce the Concern Color Code from Yellow ("volcano is restless") to Green ("volcano is dormant"). Seismicity under the volcano decreased to background levels, with weak, shallow earthquakes continuing within the volcano's edifice. Several small gas-and-steam plumes rose above the lava dome and a one-pixel thermal anomaly became less intense.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


19 December-25 December 2001

During 14-21 December, many weak shallow earthquakes occurred within the edifice of Bezymianny and other local shallow seismic events (possible avalanches) were registered. In addition, several gas-and-steam explosions occurred, with the highest reported plume rising 4 km a.s.l. and extending 60 km to the NW on 16 December at 0845. During the week, thermal anomalies were visible on satellite imagery. By 25 December a decrease in seismicity led KVERT to reduce the Concern Color Code from Orange ("eruption may occur at any time") to Yellow ("volcano is restless").

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


12 December-18 December 2001

KVERT increased the Concern Color Code at Bezymianny from Yellow ("volcano is restless") to Orange ("eruption may occur at anytime"). During 7-14 December seismicity under Bezymianny was above background levels, with the number of shallow earthquakes increasing near the end of the week. On 10 and 12-13 December gas-and-steam plumes rose to 300 m above the volcano and extended 40 km to the W, SW, and SE. Thermal anomalies were visible centered over the lava-dome area.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


5 December-11 December 2001

Seismic activity at Bezymianny remained slightly above background levels. Weak shallow earthquakes have been registered under the volcano since 10 November, becoming slightly stronger beginning on 22 November. On 10 December a four-pixel thermal anomaly was visible on satellite imagery. A faint plume with little ash extended 87 km SE from the volcano.The Alert Level was raised from Green (the lowest level) to Yellow (the second lowest level).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


8 August-14 August 2001

Volcanic activity decreased after an eruption at Bezymianny on 7 August at 1128. Later in the day, smaller explosions produced ash clouds that rose to 2 km above the dome. Seismic activity was above background levels on 7-8 August, with many small earthquakes occurring within the volcano's edifice and several different seismic signals (explosion, avalanche, collapse) recorded locally. On 9 August a three-pixel thermal anomaly was visible on satellite imagery. The anomaly represented a viscous lava flow that had formed at the dome of the volcano. On 9 August the Concern Color Code was reduced from Red (the highest level) to Yellow and was further reduced on 10 August to Green (the lowest level).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


1 August-7 August 2001

The level of Concern Color Code was raised from Yellow to Red (the highest level) on 7 August after a relatively large eruption occurred that day. Prior to the eruption, during 28 July-3 August, seismic activity was at background levels; weak, long local seismic events (possible collapses and/or avalanches) were recorded, and weak fumarolic activity was observed. On 6 August AVHRR imagery showed a three-pixel thermal anomaly on the volcano. On 7 August at 1128 an ash cloud was observed from the town of Klyuchi rising 5 km above the volcano and drifting to the ESE. By 1215 the ash cloud was at a maximum height of 10 km.

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)


25 July-31 July 2001

KVERT raised the Concern Color Code from Green to Orange on 27 July after seismic and satellite data revealed that an extrusive process began at Bezymianny's lava dome. On 23 and 24 July gas-and-steam plumes rose 200-700 m above the dome. On 25 July seismic activity at the volcano increased above background levels as shallow earthquakes and weak, long local seismic events (possible collapses and/or avalanches) were recorded. On 26 July a linear three-pixel thermal anomaly was visible on satellite imagery trending SE from the summit. The Concern Color Code was reduced to Yellow on 31 July because seismic activity was at background levels during 28-31 July and only weak fumarolic activity was observed.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


6 June-12 June 2001

The Tokyo VAAC reported that on 7 June at 0832 a possible eruption was detected on GMS-5 imagery. According to KVERT on 7 June gas-and-steam plumes rose 100 and 400m above the volcano. No seismicity was registered under the volcano. The Concern Color Code remained at Green.

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)


8 November-14 November 2000

The increase in seismicity that began on 30 October reportedly ended when seismicity decreased to background levels sometime during 3-10 November. Only gas-and-steam plumes were observed rising to a maximum height of 2 km above the volcano. KVERT lowered the Level of Concern Color Code from Yellow to Green.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)


1 November-7 November 2000

KVERT reported that an increase in seismicity began at Bezymianny on 30 October, reaching its highest level during 0320 to 0400 on 2 November. At 0626 AVHHR imagery showed that an ash plume from the volcano reached ~6.5 km a.s.l., initially extending to 50 km W of the volcano, then 130 km to the SW. At 1200 seismicity began to decrease. In addition to the AVHHR imagery, the Tokyo VAAC detected the ash cloud in GMS-5 imagery until 2332. Small ash clouds were visible on AVHRR imagery during 2 and 3 November. KVERT lowered the Level of Concern Color Code at the volcano from Orange to Yellow.

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)


Summary of eruption dates and Volcanic Explosivity Indices (VEI).

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
2010 May 21 (?) 2013 Feb 1 Confirmed 3 Historical Observations
2009 Dec 17 2010 Feb 16 (?) Confirmed 3 Historical Observations
2008 Jul 11 2008 Aug 23 (?) Confirmed 3 Historical Observations
2007 May 10 (?) 2007 Dec 24 (?) Confirmed 3 Historical Observations
2006 Apr (in or before) 2006 Dec 29 (?) Confirmed 3 Historical Observations
2005 Nov 29 (?) 2005 Dec 1 (in or after) Confirmed 2 Historical Observations
2004 Jan 14 2005 Feb (?) Confirmed 3 Historical Observations
2003 Jul 26 2003 Aug 1 (?) Confirmed 3 Historical Observations
2002 Dec 25 2002 Dec 28 (?) Confirmed 2 Historical Observations
2001 Dec 10 2002 Jan 6 (?) Confirmed 2 Historical Observations
2001 Jul 23 (?) 2001 Aug 10 (?) Confirmed 3 Historical Observations
2000 Jul 18 2000 Nov 4 (in or after) Confirmed 2 Historical Observations
2000 Mar 14 2000 Mar 26 ± 1 days Confirmed 2 Historical Observations
1999 Feb 25 1999 Feb 25 Confirmed 2 Historical Observations
1998 Jun 20 (?) 1998 Jun 22 (?) Confirmed 0 Historical Observations
1997 Dec 5 1997 Dec 6 Confirmed 3 Historical Observations
1997 May 8 1997 May 16 (?) Confirmed 3 Historical Observations
1996 Jul 23 (?) 1996 Sep 1 Confirmed 0 Historical Observations
1995 Sep (in or before) 1995 Oct 8 (?) Confirmed 3 Historical Observations
1994 Jul 7 1994 Oct 5 ± 4 days Confirmed 2 Historical Observations
1993 Oct 21 1994 Feb 4 ± 4 days Confirmed 3 Historical Observations
1992 Mar 12 1992 Jun 12 Confirmed 2 Historical Observations
1990 Jan 29 1991 Nov 29 Confirmed 3 Historical Observations
1989 Aug 1 1989 Aug 4 Confirmed 2 Historical Observations
1986 Dec 5 ± 4 days 1988 Jul 26 ± 5 days Confirmed 3 Historical Observations
1986 Mar 26 ± 5 days 1986 Jun 29 Confirmed 2 Historical Observations
1985 Jun 12 1985 Dec 14 Confirmed 3 Historical Observations
1984 Feb 5 1984 Dec Confirmed 3 Historical Observations
1981 Jun 12 1983 May 22 Confirmed 3 Historical Observations
1980 Aug 21 1980 Aug 27 ± 4 days Confirmed 2 Historical Observations
1980 Apr 18 1980 Apr 19 Confirmed 3 Historical Observations
1979 Sep 18 Unknown Confirmed 2 Historical Observations
1979 Feb 11 Unknown Confirmed 3 Historical Observations
1978 Sep 8 ± 30 days Unknown Confirmed 2 Historical Observations
1977 Mar 25 Unknown Confirmed 3 Historical Observations
1976 Mar 25 Unknown Confirmed 2 Historical Observations
1971 Mar 1974 Dec (in or after) Confirmed 3 Historical Observations
1965 Mar 9 1970 Mar Confirmed 3 Historical Observations
1964 Dec 25 1964 Dec 26 Confirmed 1 Historical Observations
1964 Jun 25 1964 Sep 20 Confirmed 2 Historical Observations
1963 May 1963 Sep (?) Confirmed 1 Historical Observations
1962 Oct 21 1962 Nov 6 Confirmed 2 Historical Observations
1961 Oct 18 1961 Dec 15 Confirmed 3 Historical Observations
1961 May 21 1961 Jun 6 Confirmed 2 Historical Observations
1961 Mar 25 1961 Mar 26 Confirmed 3 Historical Observations
1960 Apr 13 1960 Apr 14 Confirmed 2 Historical Observations
1959 Oct 15 1959 Nov 4 (?) Confirmed 1 Historical Observations
1958 Dec 28 1959 Mar 30 Confirmed 2 Historical Observations
1958 May 21 Unknown Confirmed 1 Historical Observations
1958 Jan 1958 Feb 14 Confirmed 1 Historical Observations
1957 Jul 31 1957 Jul 31 Confirmed 2 Historical Observations
1955 Oct 22 1957 Mar 1 Confirmed 5 Historical Observations
0950 (?) Unknown Confirmed 4 Tephrochronology Summit region and western flank
0850 (?) Unknown Confirmed   Tephrochronology
0700 ± 50 years Unknown Confirmed 4 Tephrochronology East summit region (Razrushenny dome)
0600 (?) Unknown Confirmed   Tephrochronology
0250 (?) Unknown Confirmed   Tephrochronology
0150 (?) Unknown Confirmed   Tephrochronology
0050 (?) Unknown Confirmed   Tephrochronology
0450 BCE (?) Unknown Confirmed 4 Radiocarbon (corrected) Tephra layer BZ
1350 BCE (?) Unknown Confirmed   Tephrochronology
1550 BCE ± 500 years Unknown Confirmed   Tephrochronology Expeditsii and Exstrusivny Greben
2750 BCE ± 500 years Unknown Confirmed   Tephrochronology
5050 BCE (?) Unknown Confirmed   Tephrochronology Pra-Bezymianny
7050 BCE ± 1000 years Unknown Confirmed   Tephrochronology Pra-Bezymianny

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title. Additional discussion of data sources can be found under Volcano Data Criteria.

Belousov A, 1996. Deposits of the 30 March 1956 directed blast at Bezymianny volcano, Kamchkatka, Russia. Bull Volc, 57: 649-662.

Belousov A B, Belousova M G, 1998. Bezymyannyi eruption on March 30, 1956 (Kamchatka): sequence of events and debris-avalanche deposits. Volc Seism, 20: 29-47 (English translation).

Belousov A, Voight B, Belousov M, 2007. Directed blasts and blast-generated pyroclastic density currents: a comparison of the Bezymianny 1956, Mount St Helens 1980, and Soufriere Hills, Montserrat 1997 eruptions and deposits. Bull Volc, 69: 701-740.

Belousov A, Voight B, Belousova M, Petukhin A, 2002. Pyroclastic surges and flows from the 8-10 May 1997 explosive eruption of Bezymianny volcano, Kamchatka, Russia. Bull Volc, 64: 455-471.

Braitseva O A, Melekestsev I V, Bogoyavlenskaya G E, Maksimov A P, 1990. Bezymiannyi volcano: eruptive history and dynamics. Volc Seism, 1990(2): 3-22 (English translation 1991, 12: 165-194).

Braitseva O A, Melekestsev I V, Ponomareva V V, Sulerzhitsky L D, 1995. Ages of calderas, large explosive craters and active volcanoes in the Kuril-Kamchatka region, Russia. Bull Volc, 57: 383-402.

Carter A, Ramsey M S, Belousov A B, 2007. Detection of a new summit crater on Bezymianny volcano lava dome: satellite and field-based thermal data. Bull Volc, 69: 811-815.

Fedotov S A, Masurenkov Y P (eds), 1991. Active Volcanoes of Kamchatka. Moscow: Nauka Pub, 2 volumes.

IAVCEI, 1973-80. Post-Miocene Volcanoes of the World. IAVCEI Data Sheets, Rome: Internatl Assoc Volc Chemistry Earth's Interior..

Kozhemyaka N N, 1995. Active volcanoes of Kamchatka: types and growth time of cones, total volumes of erupted material, productivity, and composition of rocks. Volc Seism, 16: 581-594 (English translation).

Melekestsev I V, Braitseva O A, Ponomareva V V, 1989. Prediction of volcanic hazards on the basis of the study of dynamics of volcanic activity, Kamchatka. In: Latter J H (ed), {Volcanic Hazards - Assessment and Monitoring}, Berlin: Springer-Verlag, p 10-35.

Ramsey M, Dehn J, 2004. Spaceborne observations of the 2000 Bezymianny, Kamchatka eruption: the integration of high-resolution ASTER data into near real-time monitoring using AVHRR. J Volc Geotherm Res, 135: 127-146.

Seleznev B V, Dvigalo V N, Gusev N A, 1983. Evolution of Bezymyannai volcano from stereoscopic plotting of aerial photographs of 1950, 1967 and 1976-1981. Volc Seism, 1983(1): 52-64 (English translation 1984, 5: 53-66).

Thelen W, West M, Senyukov S, 2010. Seismic characterization of the fall 2007 eruptive sequence at Bezymianny Volcano, Russia. J Volc Geotherm Res, 194: 201-213.

Vlodavetz V I, Piip B I, 1959. Kamchatka and Continental Areas of Asia. Catalog of Active Volcanoes of the World and Solfatara Fields, Rome: IAVCEI, 8: 1-110.

Prior to its noted 1955-56 eruption, Bezymianny volcano had been considered extinct. The modern Bezymianny, much smaller in size than its massive neighbors Kamen and Kliuchevskoi, was formed about 4700 years ago over a late-Pleistocene lava-dome complex and an ancestral volcano that was built between about 11,000-7000 years ago. Three periods of intensified activity have occurred during the past 3000 years. The latest period, which was preceded by a 1000-year quiescence, began with the dramatic 1955-56 eruption. This eruption, similar to that of Mount St. Helens in 1980, produced a large horseshoe-shaped crater that was formed by collapse of the summit and an associated lateral blast. Subsequent episodic but ongoing lava-dome growth, accompanied by intermittent explosive activity and pyroclastic flows, has largely filled the 1956 crater.