About Bolshoi Semiachik
Bolshoi Semiachik is a stratovolcano(es) rising to 1,720 meters (5,643 feet) in Russia's Northwestern Pacific Volcanic Regions. The volcano is currently active, with its most recent eruption in 4450 BCE. The volcano has produced 2 recorded eruptions.
Geography & Climate
Bolshoi Semiachik is located in Russia, within the Eastern Kamchatka Volcanic Arc of the broader Northwestern Pacific Volcanic Regions. Situated at 54.32° N, 160.02° E in the Northern Hemisphere, the volcano lies within a temperate climate zone. With a summit elevation of 1,720 meters above sea level, Bolshoi Semiachik is a moderately sized peak that remains accessible to hikers and researchers for much of the year. The volcanic landform is characterized as a composite, which describes the physical shape and structure of the volcanic edifice as observed from the surface.
Geological Context
Bolshoi Semiachik sits in a subduction zone, where one tectonic plate dives beneath another, creating intense heat and pressure that generates magma. Subduction zones are responsible for many of the world's most explosive volcanoes and deadliest eruptions. For communities in Russia near Bolshoi Semiachik, this tectonic setting means the volcano is capable of producing powerful explosive eruptions, pyroclastic flows, and lahars that can threaten populated areas within tens of kilometers of the summit. The dominant rock type is basalt / picro-basalt, a dark, fine-grained volcanic rock that forms from rapidly cooling, low-viscosity lava. Basaltic eruptions tend to be less explosive and produce fluid lava flows that can travel long distances. While less immediately dangerous than explosive eruptions, basaltic lava flows can destroy structures and infrastructure in their path, and volcanic gases released during these eruptions can affect air quality over a wide area.
Eruption History Summary
Bolshoi Semiachik has 2 recorded eruptions in the geological database, spanning from 6800 BCE to 4450 BCE. These eruptions span roughly 2,350 years of volcanic history.
GVP Reference Summary
The Bolshoi Semiachik volcanic complex was constructed within a 10-km-wide caldera whose rim is exposed only on the west. The caldera occupies a large 20 x 30 km late-Pleistocene volcano-tectonic depression near the Pacific Coast of eastern Kamchatka. Post-caldera volcanism includes resurgent doming and the construction of numerous stratovolcanoes and lava domes, several of which have been active during the Holocene. Zubchatka (Bolshoi Semiachik), Zapadny Barany, Vostochny Barany, Zentralny Semiachik, Popkov, Plosky, and Burlyashchy volcanoes are the largest of the complex. The youngest volcanism and intense hydrothermal activity is located outside the caldera to the SE.
— Smithsonian Institution, Global Volcanism Program
2 Recorded Eruptions
| Year | VEI | Type | Area |
|---|---|---|---|
| 4450 BCE | — | Confirmed Eruption | Korona and Yezh lava domes |
| 6800 BCE | — | Confirmed Eruption | Ivanov lava dome |
Real-Time Data
USGS Alert Level
Thermal Anomalies
Frequently Asked Questions About Bolshoi Semiachik
Is Bolshoi Semiachik an active volcano?+
Bolshoi Semiachik is not currently classified as active. Its activity evidence is listed as "Eruption Dated." The last known eruption was in 4450 BCE. However, no volcano is ever considered permanently extinct.
When did Bolshoi Semiachik last erupt?+
The most recent recorded eruption of Bolshoi Semiachik occurred in 4450 BCE. The eruption was classified as a "Confirmed Eruption." Bolshoi Semiachik has 2 recorded eruptions in total.
How high is Bolshoi Semiachik?+
Bolshoi Semiachik has a summit elevation of 1,720 meters (5,643 feet) above sea level. At 1,720 meters, it is a moderately sized volcanic peak, roughly comparable to Mount Vesuvius (1,281m).
What type of volcano is Bolshoi Semiachik?+
Bolshoi Semiachik is classified as a Stratovolcano(es). Stratovolcano(es) volcanoes have distinct geological characteristics that set them apart from other volcanic types.
Where is Bolshoi Semiachik located?+
Bolshoi Semiachik is located in Russia, in the Northwestern Pacific Volcanic Regions. More specifically, it lies within the Eastern Kamchatka Volcanic Arc. Its exact coordinates are 54.320° latitude, 160.020° longitude.
Is it safe to visit Bolshoi Semiachik?+
Bolshoi Semiachik can generally be visited, but as with any volcano, visitors should check local conditions and any advisory notices before traveling. Russia may have specific regulations for accessing volcanic areas. Guided tours are often the safest and most informative way to experience a volcano.
