About Nantaisan
Nantaisan is a stratovolcano rising to 2,486 meters (8,157 feet) in Japan's Northwestern Pacific Volcanic Regions. The volcano is currently active, with its most recent eruption in 9540 BCE. The volcano has produced 1 recorded eruption.
Geography & Climate
Nantaisan is located in Japan, within the Northeast Japan Volcanic Arc of the broader Northwestern Pacific Volcanic Regions. Situated at 36.77° N, 139.49° E in the Northern Hemisphere, the volcano lies within a temperate climate zone. At 2,486 meters above sea level, Nantaisan rises above the surrounding terrain into montane or subalpine conditions. The elevation creates distinct ecological zones along its flanks, from forested lower slopes to exposed rocky terrain near the summit. 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
Nantaisan 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 Japan near Nantaisan, 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
Nantaisan has 1 recorded eruption in the geological database, spanning from 9540 BCE to 9540 BCE.
GVP Reference Summary
Nantaisan stratovolcano rises above the north shore of Lake Chuzenji in Nikko National Park, and forms a backdrop to the temple complex there. Lava flows from the early stage of edifice construction dammed the Daiyo River, forming Lake Chuzenji; the Kegon waterfall plunges over this barrier. Nantaisan has an asymmetrical profile when viewed from the west as a result of late-stage collapse on the north side. Two major late-stage eruptions ejected large amounts of scoria, followed by the emission of pyroclastic flows. The latest effusive activity produced the Osawa lava flow, a thick, viscous dacitic flow that traveled from the breached crater down the N flank. The Bentengawara pyroclastic-flow deposit, representing the latest known eruptive activity, was radiocarbon dated at about 10,000 years Before Present and was emplaced following a quiescent period of about 3,000 years.
— Smithsonian Institution, Global Volcanism Program
1 Recorded Eruption
| Year | VEI | Type | Area |
|---|---|---|---|
| 9540 BCE | — | Confirmed Eruption | — |
Real-Time Data
USGS Alert Level
Thermal Anomalies
Frequently Asked Questions About Nantaisan
Is Nantaisan an active volcano?+
Nantaisan is not currently classified as active. Its activity evidence is listed as "Eruption Dated." The last known eruption was in 9540 BCE. However, no volcano is ever considered permanently extinct.
When did Nantaisan last erupt?+
The most recent recorded eruption of Nantaisan occurred in 9540 BCE. The eruption was classified as a "Confirmed Eruption." Nantaisan has 1 recorded eruption in total.
How high is Nantaisan?+
Nantaisan has a summit elevation of 2,486 meters (8,157 feet) above sea level. At 2,486 meters, it is comparable in height to many significant mountain peaks and stands well above the tree line.
What type of volcano is Nantaisan?+
Nantaisan 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 Nantaisan located?+
Nantaisan is located in Japan, in the Northwestern Pacific Volcanic Regions. More specifically, it lies within the Northeast Japan Volcanic Arc. Its exact coordinates are 36.765° latitude, 139.491° longitude.
Is it safe to visit Nantaisan?+
Nantaisan can generally be visited, but as with any volcano, visitors should check local conditions and any advisory notices before traveling. Japan may have specific regulations for accessing volcanic areas. Guided tours are often the safest and most informative way to experience a volcano.
