Report on Bezymianny (Russia) — December 2001
Bulletin of the Global Volcanism Network, vol. 26, no. 12 (December 2001)
Managing Editor: Richard Wunderman.
Bezymianny (Russia) Dark mid-December 2001 plume reaches 4 km above dome
Please cite this report as:
Global Volcanism Program, 2001. Report on Bezymianny (Russia). In: Wunderman, R. (ed.), Bulletin of the Global Volcanism Network, 26:12. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN200112-300250.
55.972°N, 160.595°E; summit elev. 2882 m
All times are local (unless otherwise noted)
During September 2001 through early January 2002, seismicity at Bezymianny remained at or near background levels, although one mid-December outburst was striking. Weak fumarolic activity was observed on 15, 18, and 20 September, on 8, 12, 27, and 29 October, on 1 November, and during 1-2, 6, and 8-10 January. Weak shallow earthquakes were registered under the volcano beginning on 10 November. The earthquakes became stronger beginning on 22 November, but seismicity remained near background levels. Gas-and-steam plumes were observed throughout the report period reaching 50-800 m above the dome and extending up to 60 km from the volcano.
On 16 December, a plume reached 4 km above the dome and extended 60 km NW. The plume appeared dark from 20 km away. Plumes on 8-10 January extended 5-20 km S and NW. On 10 and 12-13 December, gas-and-steam plumes rose to 300 m above the volcano and extended 40 km W, SW, and SE.
Thermal anomalies were observed on satellite imagery several times during December 2001 and early January 2002 (table 1). On 10 December, a four-pixel thermal anomaly was visible, along with a faint, ash-poor plume that extended 87 km SE from the volcano.
|Date||Local Time||Pixels||Recovery pixels||Maximum band-3 temperature||Background temperature|
|10 Dec 2001||0617||4||--||10.3°C||-29°C|
|12 Dec 2001||1658||4||2-3||~49°C||-27 to -28°C|
|13 Dec 2001||0644||4||2-3||~49°C||-27 to -28°C|
|13 Dec 2001||1635||10||--||33.8°C||-14°C|
|14 Dec 2001||0622||10||2||48.2°C||-22°C|
|14 Dec 2001||1611||14||--||49.5°C||-13°C|
|15 Dec 2001||0559||5||1||48.5°C||-36°C|
|21 Dec 2001||0446||1||--||9.8°C||-28.3°C|
|21 Dec 2001||1834||1||--||-3.44°C||-30°C|
|22 Dec 2001||1810||1||--||-14.03°C||-30°C|
|25 Dec 2001||morning||1||--||-8°C||-30°C|
|31 Dec 2001||0621||1||--||-14°C||-26°C|
|01 Jan 2002||1703||1||--||-7.3°C||-24°C|
|06 Jan 2002||1707||1||--||-6°C||-23°C|
The Concern Color Code was raised from Green ("volcano is dormant" ) to Yellow ("volcano is restless"). Activity increased during 14-21 December, when many weak shallow earthquakes occurred within the edifice and other local shallow seismic events (possible avalanches) were registered. The Concern Color Code was increased to Orange ("eruption may occur at any time") until around 25 December, when seismicity decreased again. The Concern Color Code was reduced to Green by the end of 2001 and remained there through at least 25 January.
Geologic Background. Prior to its noted 1955-56 eruption, Bezymianny had been considered extinct. The modern volcano, 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 edifice built 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 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.
Information Contacts: Olga Chubarova, Kamchatka Volcanic Eruptions Response Team (KVERT) (URL: http://www.kscnet.ru/ivs/kvert/); Tom Miller, Alaska Volcano Observatory (AVO) (URL: https://www.avo.alaska.edu/); Tokyo Volcanic Ash Advisory Center, Tokyo, Japan (URL: https://ds.data.jma.go.jp/svd/vaac/data/).