Report on Bezymianny (Russia) — November 1993
Bulletin of the Global Volcanism Network, vol. 18, no. 11 (November 1993)
Managing Editor: Richard Wunderman.
Bezymianny (Russia) Still restless after strong October eruption, but tremor declines
Please cite this report as:
Global Volcanism Program, 1993. Report on Bezymianny (Russia) (Wunderman, R., ed.). Bulletin of the Global Volcanism Network, 18:11. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199311-300250.
55.972°N, 160.595°E; summit elev. 2882 m
All times are local (unless otherwise noted)
. . . more subdued eruptive activity followed during November through mid-December. On 15 November, the town of Kliuchi, ~50 km NNE of Bezymianny, received weak ashfall. On 18 November, a steam-and-gas plume containing a small amount of ash rose 3-4 km above Bezymianny's crater rim. The plume extended toward the N and E for more than 60 km. During the last week of November, weak tremor shook for 3-8 hours/day, dropping to 2-3 hours/day during the first week of December. By mid-December, the tremor level fell to about background levels.
The KVERT characterizes Kamchatkan volcanoes with a Level of Concern Color Code. The Code was last reported on 4 December as Yellow, indicating the volcano is restless.
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: V. Kirianov, IVGG.