Report on Avachinsky (Russia) — March 1996
Bulletin of the Global Volcanism Network, vol. 21, no. 3 (March 1996)
Managing Editor: Richard Wunderman
Avachinsky (Russia) Increased seismicity and a higher steam plume
Please cite this report as:
Global Volcanism Program, 1996. Report on Avachinsky (Russia). In: Wunderman, R (ed.), Bulletin of the Global Volcanism Network, 21:3. Smithsonian Institution. http://dx.doi.org/10.5479/si.GVP.BGVN199603-300100.
53.256°N, 158.836°E; summit elev. 2717 m
All times are local (unless otherwise noted)
On 7 March the Institute of Volcanic Geology and Geochemistry (IVGG) reported a noteworthy increase in seismicity beneath Avachinsky and an increase in the height of the steam plume to ~100 m above the volcano. The steam plume suggested a possible increase in heat flux. The IVGG reported that the possibility of an eruption within the next few weeks to months has increased significantly. Elevated seismicity was previously reported in late 1993 and early 1994 (BGVN 19:01).
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: Tom Miller, Alaska Volcano Observatory (see Akutan); Vladimir Kirianov, Institute of Volcanic Geology and Geochemistry, Piip Ave. 9, Petropavlovsk-Kamchatsky, 683006, Russia.