Norikuradake

Geography & Climate

Norikuradake is located in Japan, within the Nankai Volcanic Arc of the broader Western Pacific Volcanic Regions. Situated at 36.11° N, 137.55° E in the Northern Hemisphere, the volcano lies within a temperate climate zone. At 3,026 meters above sea level, Norikuradake 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

Norikuradake 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 Norikuradake, 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

Norikuradake has 3 recorded eruptions in the geological database, spanning from 7700 BCE to 50 BCE. The most powerful recorded event was a severe eruption capable of regional ash fall and pyroclastic flows in 50 BCE, reaching VEI 3 on the Volcanic Explosivity Index. Notable eruptions include 50 BCE (VEI 3), 7250 BCE (VEI 3), 7700 BCE (VEI 3). These eruptions span roughly 7,650 years of volcanic history.

Significance

With a maximum recorded VEI of 3, Norikuradake has produced eruptions capable of generating pyroclastic flows and significant ash fall in the surrounding area. While not among the largest eruptions globally, VEI 3 events pose serious hazards to local populations and can disrupt regional air travel.

GVP Reference Summary

Norikuradake volcano consists of an elongated group of small andesitic stratovolcanoes and craters arranged along a N-S line above a ridge crest in the southern part of the Northern Japan Alps. The 3026-m-high andesitic-to-dacitic volcano is the third highest in Japan and lies at the center of the Norikura volcanic zone extending from Yakedake on the north to Ontake on the south. Early eruptions occurred at both the northern and southern ends of the present-day volcano, forming stratovolcanoes that have been largely buried by later southward-migrating eruptions. It was active during the early Holocene, and the last eruption took place about 2000 years ago.

— Smithsonian Institution, Global Volcanism Program