Report on Avachinsky (Russia) — May 1992
Bulletin of the Global Volcanism Network, vol. 17, no. 5 (May 1992)
Managing Editor: Lindsay McClelland.
Avachinsky (Russia) Fumarolic activity around 1991 dome
Please cite this report as:
Global Volcanism Program, 1992. Report on Avachinsky (Russia). In: McClelland, L (ed.), Bulletin of the Global Volcanism Network, 17:5. Smithsonian Institution. http://dx.doi.org/10.5479/si.GVP.BGVN199205-300100.
53.256°N, 158.836°E; summit elev. 2717 m
All times are local (unless otherwise noted)
Fumarolic activity was occurring from numerous points around the margins of the January 1991 lava dome during a 13 May overflight. Numerous circumferential and radial fissures, previously observed in October 1991, covered the dome's surface, but the small lava flows that extended down the SSE and SW flanks were no longer visible.
Geologic Background. Avachinsky, one of Kamchatka's most active volcanoes, rises above Petropavlovsk, Kamchatka's largest city. Avachinsky began to form during the middle or late Pleistocene and is flanked to the SE by the parasitic volcano Kozelsky, which has a large crater breached to the NE. It has a large horseshoe-shaped caldera, breached to the SW, that was formed when a major debris avalanche about 30,000-40,000 years ago buried an area of about 500 sq km to the south underlying the city of Petropavlovsk. Reconstruction of the volcano took place in two stages, the first of which began about 18,000 years before present (BP), and the second 7000 years BP. Most eruptive products have been explosive, with pyroclastic flows and hot lahars being directed primarily to the SW by the breached caldera, although relatively short lava flows have been emitted. The frequent historical eruptions have been similar in style and magnitude to previous Holocene eruptions.
Information Contacts: H. Gaudru, SVE, Switzerland; G. de St. Cyr, T. de St. Cyr, and I. de St. Cyr, Lyon, France; T. Vaudelin, Genève, Switzerland.