About Ketoi
Ketoi is a stratovolcano rising to 1,172 meters (3,845 feet) in Russia's Northwestern Pacific Volcanic Regions. It last erupted in 1960 CE, and volcanologists consider it an active volcanic system. The volcano has produced 5 recorded eruptions, with a maximum Volcanic Explosivity Index (VEI) of 2.
Geography & Climate
Ketoi is located in Russia, within the Kuril Volcanic Arc of the broader Northwestern Pacific Volcanic Regions. Situated at 47.35° N, 152.47° E in the Northern Hemisphere, the volcano lies within a temperate climate zone. With a summit elevation of 1,172 meters above sea level, Ketoi 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
Ketoi 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 Ketoi, 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 andesite / basaltic andesite, 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
Ketoi has 5 recorded eruptions in the geological database, spanning from 1843 CE to 2018 CE. The most powerful recorded event was an explosive event producing ash plumes up to several kilometers in 1960 CE, reaching VEI 2 on the Volcanic Explosivity Index. This eruption frequency indicates a moderately active volcanic system with periodic reawakenings. With eruptive activity as recently as 2018 CE, Ketoi remains an actively monitored volcano.
Significance
With 5 recorded eruptions on file, Ketoi has enough documented activity to help scientists identify patterns in its eruptive behavior. Given its recent activity, Ketoi is closely monitored by geological survey organizations to provide early warning of future unrest.
GVP Reference Summary
The circular 10-km-wide Ketoi island, which rises across the 19-km-wide Diana Strait from Simushir Island, hosts of one of the most complex volcanic structures of the Kuril Islands. The rim of a 5-km-wide Pleistocene caldera is exposed only on the NE side. A younger stratovolcano forming the NW part of the island is cut by a horst-and-graben structure containing two solfatara fields. A 1.5-km-wide freshwater lake fills an explosion crater in the center of the island. Pallas Peak, a large andesitic cone in the NE part of the caldera, is truncated by a 550-m-wide crater containing a brilliantly colored turquoise crater lake. Lava flows from Pallas Peak overtop the caldera rim and descend nearly 5 km to the SE coast. The first historical eruption of Pallas Peak, during 1843-46, was its largest.
— Smithsonian Institution, Global Volcanism Program
5 Recorded Eruptions
| Year | VEI | Type | Area |
|---|---|---|---|
| 2018 | 1 | Uncertain Eruption | — |
| 2013 | — | Uncertain Eruption | Pallas Peak |
| 1960 | 2 | Confirmed Eruption | Pallas Peak |
| 1924 | 2 | Confirmed Eruption | Pallas Peak |
| 1843 | 2 | Confirmed Eruption | Pallas Peak |
Real-Time Data
USGS Alert Level
Thermal Anomalies
Frequently Asked Questions About Ketoi
Is Ketoi an active volcano?+
Yes, Ketoi is considered an active volcano. Its most recent eruption was in 1960 CE. The volcano is monitored by geological agencies, and its activity status is based on observed eruptions within recorded history.
When did Ketoi last erupt?+
The most recent recorded eruption of Ketoi occurred in 2018 CE with a Volcanic Explosivity Index (VEI) of 1. The eruption was classified as a "Uncertain Eruption." Ketoi has 5 recorded eruptions in total.
How high is Ketoi?+
Ketoi has a summit elevation of 1,172 meters (3,845 feet) above sea level. At 1,172 meters, it is a moderately sized volcanic peak, roughly comparable to Mount Vesuvius (1,281m).
What type of volcano is Ketoi?+
Ketoi is classified as a Stratovolcano. Stratovolcanoes (also called composite volcanoes) are steep, conical volcanoes built up by many layers of hardened lava, tephra, and volcanic ash. They are among the most common and dangerous types, known for explosive eruptions.
Where is Ketoi located?+
Ketoi is located in Russia, in the Northwestern Pacific Volcanic Regions. More specifically, it lies within the Kuril Volcanic Arc. Its exact coordinates are 47.350° latitude, 152.475° longitude.
Is it safe to visit Ketoi?+
Visiting Ketoi requires checking current volcanic activity and alert levels. As an active volcano with eruptions as recent as 1960 CE, conditions can change rapidly. Always consult local geological authorities and follow official warnings before visiting. Many active volcanoes have designated safe viewing areas and guided tour options.
