Report on Bezymianny (Russia) — January 2016
Bulletin of the Global Volcanism Network, vol. 41, no. 1 (January 2016)
Managing Editor: Edward Venzke. Edited by A. Elizabeth Crafford.
Bezymianny (Russia) Minor seismic event interpreted as lava extrusion in June 2014; incandescence in August 2014
Please cite this report as:
Global Volcanism Program, 2016. Report on Bezymianny (Russia) (Crafford, A.E., and Venzke, E., eds.). Bulletin of the Global Volcanism Network, 41:1. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN201601-300250.
55.972°N, 160.595°E; summit elev. 2882 m
All times are local (unless otherwise noted)
Weekly reports issued by the Kamchatka Volcanic Eruption Response Team (KVERT) are the primary data source for activity at this remote volcano on the Kamchatka Peninsula. No thermal anomalies were reported by MODVOLC, nor were there any Volcanic Ash Advisory Reports issued, during 2014 or 2015.
KVERT described "moderate activity of the volcano" from January through mid-June 2014, and "weak" activity for the rest of 2014 and all of 2015. This was characterized by weak or no seismicity, weak or moderate gas-and-steam emissions or fumarolic activity, and weak thermal anomalies observed from satellite data on the uncommon days that the volcano was not obscured by clouds.
There were few exceptions to this characterization in 2014. During the first two weeks of May, video data revealed moderate-to-strong gas-and-steam emissions, and weak gas-and-steam emissions were reported in late May and early June, shortly before a seismic activity increase. Weak and moderate gas-and-steam activity was reported until mid-November, after which only "weak" activity was reported for the rest of 2014 and most of 2015.
On 17 June 2014, seismic activity increased and 12 shallow seismic events were recorded. This was interpreted by KVERT as an extrusion of lava at the top of the dome, and caused an increase in the Aviation Color Code from Yellow to Orange (on a four color scale of Green-Yellow-Orange-Red). Shallow seismic events were recorded for approximately three weeks, and on 17 July the Color Code was lowered back to Yellow. Weak seismic activity was reported for the rest of the year.
A visual inspection of the volcano on 17 August 2014 revealed incandescence at the summit.
Beginning on 16 January 2015, strong seismicity of neighboring Klyuchevskoy volcano obscured seismicity data at Bezymianny, so it was not reported for the rest of the year. Moderate gas-and-steam activity was observed during the week ending on 23 January, 11-16 April, and from 16 July through 3 September 2015. Otherwise, fumarolic activity was merely observed from video data. Weak thermal anomalies were reported by KVERT as observed in satellite images on clear days throughout the year.
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: Kamchatka Volcanic Eruptions Response Team (KVERT), Far East Division, Russian Academy of Sciences, 9 Piip Blvd., Petropavlovsk-Kamchatsky, 683006, Russia (URL: http://www.kscnet.ru/ivs/)