Bezymianny

{{Short description|Stratovolcano on the Kamchatka peninsula, Russia}}

{{Infobox mountain

| name = Bezymianny

| native_name ={{native name|ru|Безымянный}}

| photo = Kamchatka Bezy Kliyu Kamen.jpg

| photo_size = 250px

| photo_caption = Kamchatka volcanoes: Klyuchevskaya Sopka (up), Bezymianny (down), both in activity, and the Kamen (middle).

| map = Russia Kamchatka Krai

| map_caption =

| map_relief = yes

| location = Kamchatka, Russia

| elevation_m = 3,020

| elevation_ref =

| listing =

| translation = Nameless

| language = Russian

| pronunciation =

| range= Eastern Range

| coordinates = {{coord|55|58|42|N|160|35|12|E|type:mountain}}

| coordinates_ref = {{cite web|title=Bezymianny|url=https://www.volcanodiscovery.com/bezymianny.html|website=www.volcanodiscovery.com|publisher=Volcano Discovery}}

| topo =

| type = Stratovolcano

| age = 4700 years old

| volcanic_field = Kliuchevskoya Volcanic Group

| last_eruption = April 11, 12, and 13 2023 (ongoing)

}}

Bezymianny ({{langx|ru|Безымянный}} Bezymyannyyi, meaning unnamed) is an active stratovolcano in Kamchatka, Russia. Bezymianny volcano had been considered extinct until 1955. Activity started in 1955, culminating in a dramatic eruption on 30 March 1956.{{cite journal|last1=Gorshkov|first1=G. S.|title=Gigantic eruption of the volcano bezymianny|journal=Bulletin Volcanologique|date=December 1959|volume=20|issue=1|pages=77–109|doi=10.1007/BF02596572|bibcode=1959BVol...20...77G |s2cid=129408765|url=http://repo.kscnet.ru/1237/1/gorshkov-1959-BV20.pdf }}{{cite book |last=Kirianov |first=Vladimir Yu |year=1994 |chapter=Volcanic Ash in Kamchatka as a Source of Potential Hazard to Air Traffic |chapter-url=https://pubs.usgs.gov/bul/2047/report.pdf |title=Volcanic Ash and Aviation Safety: Proceedings of the First International Symposium on Volcanic Ash and Aviation Safety |editor-last=Casadevall |editor-first=Thomas J. |series=U.S. Geological Survey Bulletin |volume=2047 |page=60}} This eruption, similar to the 1980 eruption of Mount St. Helens, produced a large horseshoe-shaped crater that was formed by a sector collapse 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. The most recent eruption of lava flows occurred in February 2013.{{cite web | url=http://www.kscnet.ru/ivs/kvert/van/index.php?n=05-2013 | title=VONA/KVERT Weekly Information Release 05-2013 - Kamchatkan and Northern Kuriles Volcanic Activity - January 31, 2013, 23:31 UTC (February 01, 2013, 11:31 KST) | publisher=Kamchatka Volcanic Eruption Response Team | date=1 February 2013 | accessdate=26 February 2016}} An explosive eruption on 20 December 2017 released an ash plume rising to a height of {{convert|15|km|ft}} above sea level, which drifted for {{convert|320|km}} NE.[http://volcano.si.edu/volcano.cfm?vn=300250 Global Volcanism Program, 2017. Report on Bezymianny (Russia). In: Sally Kuhn Sennert, Weekly Volcanic Activity Report, 20–26 December 2017. Smithsonian Institution and US Geological Survey.] The volcano erupted similarly on 28 May 2022, again spewing an ash plume over {{convert|15|km|ft}} high.{{cite web |title=Bezymianny volcano (Kamchatka): massive, possibly sub-plinian eruption today |website=Volcano Discovery |date=28 May 2022 |url=https://www.volcanodiscovery.com/bezymianny/news/181915/Bezymianny-volcano-Kamchatka-massive-possibly-sub-plinian-eruption-today.html |access-date=28 May 2022}} On April 7, 2023, Russia reported Bezymianny had erupted explosively again and the Federal Agency for Air Transport, Rosaviatsiya, issued a Notice to Airmen (NOTAM) and raised the aviation Color Code Red. The eruption formed a column of ash that rose to a height of {{convert|12|km|ft}} and was drifting to the southeast slowly. The ash plume stretched out across a distance of {{convert|2000|km}}.{{cn|date=June 2024}}

The modern Bezymianny volcano, much smaller than its massive neighbors Kamen and Kliuchevskoi, was formed about 4700 years ago over a late-Pleistocene lava-dome complex and an ancestral volcano that was built between about 11,000–7000 years ago. There have been three periods of intensified activity in the past 3000 years.