|Range/Region:||South Central Zagros|
|Best months for climbing:||Mar, Apr, May, Jun, Jul, Aug, Sep, Oct|
|Most recent eruption:||2006>(continuing)|
|Year first climbed:||1965|
|First successful climber(s):||V. Maligin|
|Nearest major airport:||Kamen village|
|Convenient Center:||Kamen village|
Bezymianny is located on the southeast slope of the extinct volcano Kamen. These two volcanoes are separated by a high, narrow saddle. The east and west slopes of Bezymianny are cut by two wide and sloping valleys. Several lava flows can be found on the upper portions of its slopes. Lower in elevation, a row of domes exist along the southern and western sides of the volcano. Bezymianny is located on a fault which runs in a northeast to southwest direction. A large portion of the volcano is made of a thick mass of light gray hornblende and andesites. Most of these lavas on the lower slopes of Bezymianny are covered by loose pyroclastic deposits. The building of Bezymianny took place in several stages. During later stage, an explosive crater was formed on the top of the volcano. Many flows of lava composed of darker augite andesites originating from this crater partly reaching the bottom of the volcano. Over time smaller eruptions continued and formed small volcanic cones on the southern and western slopes of the volcano.
Bezymianny means "no name", a designation earned because the volcano had not erupted in historic time and it was over-shadowed by its neighbors, spectacular volcanoes like Kliuchevskoi. The volcano reawakened in 1955. About September 29, 1955, the number of earthquakes began to increase beneath the volcano. On October 22, the volcano began to erupt, throwing ash 3-5 miles (5-8 km) into the air. Pressure was building in the volcano and had pushed an old dome up more than 300 feet (100 m). Macdonald (1972, p. 226-227) used the study of Gorshkov (1959) to describe the climatic eruption:
"On March 30 a tremendous explosion destroyed the top of the mountain, lowering the height of the summit some 600 feet and forming a crater roughly a mile across. A great Vulcanian cloud was projected obliquely upward toward the east at an angle of 30-40 degrees to the horizon, reaching a height of 24 miles. At a distance of 15 miles, trees a foot in diameter were felled by the force of the blast. Eighteen miles away the bark of living trees was scorched and dead wood was set afire. Snow 3 to 6 feet deep was melted by hot ash along the center line of the blast. Simultaneously, great glowing avalanches swept down the mountain slopes, particularly into the Dry Hapitsa Valley. Six to eight miles east of the crater the ground was covered with sandy ash 1.5 feet thick, and 11 miles away the valley of the river was completely filled with deposits from the glowing avalanche. The avalanche gave rise to mudflows that continued down the valley."
This description of Bezymianny after the climatic eruption are remarkable similar to the May 18, 1980 eruption of Mount St. Helens
Thanks to Brian Garrett for this description.