Raikoke

Geography & Climate

Raikoke is located in Russia, within the Kuril Volcanic Arc of the broader Northwestern Pacific Volcanic Regions. Situated at 48.29° N, 153.25° E in the Northern Hemisphere, the volcano lies within a temperate climate zone. With a summit elevation of 551 meters above sea level, Raikoke 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

Raikoke 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 Raikoke, 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

Raikoke has 4 recorded eruptions in the geological database, spanning from 1765 CE to 2019 CE. The most powerful recorded event was a cataclysmic eruption with ash columns reaching the stratosphere in 1924 CE, reaching VEI 4 on the Volcanic Explosivity Index. Notable eruptions include 2019 CE (VEI 3), 1924 CE (VEI 4), 1778 CE (VEI 4). These eruptions span roughly 254 years of volcanic history. With eruptive activity as recently as 2019 CE, Raikoke remains an actively monitored volcano.

Significance

With a maximum recorded VEI of 4, Raikoke has demonstrated the capacity for significant explosive eruptions that can impact regional aviation, agriculture, and communities tens of kilometers from the summit. VEI 4 eruptions produce ash columns reaching 15-25 kilometers into the atmosphere. Given its recent activity, Raikoke is closely monitored by geological survey organizations to provide early warning of future unrest.

GVP Reference Summary

A low truncated volcano forms the small barren Raikoke Island, which lies 16 km across the Golovnin Strait from Matua Island in the central Kuriles. The oval-shaped basaltic island is only 2 x 2.5 km wide and rises above a submarine terrace. An eruption in 1778, during which the upper third of the island was said to have been destroyed, prompted the first volcanological investigation in the Kuril Islands two years later. Incorrect reports of eruptions in 1777 and 1780 were due to misprints and errors in descriptions of the 1778 event (Gorshkov, 1970). Another powerful eruption in 1924 greatly deepened the crater and changed the outline of the island. Prior to a 2019 eruption, the steep-walled crater, highest on the SE side, was 700 m wide and 200 m deep. Lava flows mantle the eastern side of the island.

— Smithsonian Institution, Global Volcanism Program