Mount Taishaku

Omanago Group

Lava dome · Japan · 2341m

The Omanago volcano group (upper left) consists of a series of five lava domes in Nikko National Park. The highest dome is Omanago, located at the SE end of the complex. Mitsudake is the NW-most dome. The higher northern peak of the Mitsudake complex is out of view to the left, and the lower southern dome forms the low ridge behind the hot spring resort of Yunoko lake in the center of the photo. The peak on the right horizon is Nantaisan. · Photo: Photo by Lee Siebert, 1964 (Smithsonian Institution). · Wikimedia Commons

Type: Lava dome
Country: Japan
Region: Northwestern Pacific Volcanic Regions / Northeast Japan Volcanic Arc
Elevation: 2341m
Coordinates: 36.807, 139.476
Last eruption: -3050
Tectonic setting: Subduction zone / Continental crust (> 25 km)
Landform: Cluster
Major rock type: Dacite

Geological summary

The Omanago volcano group consists of a series of five closely spaced lava domes that were constructed north and NW of Nantai volcano in Nikko National Park. The highest of the dacitic domes is Omanago, which later erupted andesitic lavas. The Mitsudake dome, which overlooks the hot spring resort of Lake Yunoko, was radiocarbon dated at about 5,000 years ago. Mitsudake was constructed on a southerly dipping slope, so that the southern of its two flat-topped domes is lower, and is overlapped by sediments of the Senjogahara plain.

Eruption history

Summary (VEI over time)

Click a bar to see individual eruptions

Detailed timeline

3050 BCEVEI ?Geological estimate
BCE 3050 – Ongoing
Mitsu-dake

External links

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🔗 Smithsonian GVP source page

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