Nikko
Stratovolcano in Japan
Key Facts
Elevation
-392 m (-1,286 ft)
Type
Stratovolcano
Location
23.078°, 142.326°
Region
Mariana Volcanic Arc
Rock Type
Basalt / Picro-Basalt
Tectonic Setting
Subduction zone
Location
Loading map...
Overview
Nikko submarine volcano is a massive seamount that rises from nearly 3 km depth to within 392 m of the ocean surface near the N end of the Mariana Volcanic Arc. Two large cones at the basaltic-to-andesitic volcano have been constructed on the NW and NE rims of a roughly 3-km-wide, flat-floored submarine caldera, whose rim is prominently displayed on the southern side, but largely buried on the north. A smaller cone is present on the SE caldera floor.
The larger NW cone lies within a partially buried crater and displays hydrothermal activity. Discolored water was observed in July 1979, but none has been observed during semi-regular seasonal reconnaissance flights since then. Hydrothermal venting was documented during a NOAA expedition.
Volcanic Hazards & Risk Assessment
Primary Hazards
- Pyroclastic flows
- Lava flows
- Volcanic bombs and ballistics
- Lahars and mudflows
Risk Level
Geological Composition & Structure
Rock Types
Tectonic Setting
Age & Formation
Eruption Statistics & Analysis
| Metric | Value | Global Ranking | Significance |
|---|---|---|---|
| Total Recorded Eruptions | Unknown | Low | Moderately active volcano |
| Maximum VEI | VEI Unknown | Minor | Local impact potential |
| Recent Activity | Unknown | Historical | Historically active |
Monitoring & Alert Status
Monitoring Networks
Current Status
Nearby Volcanoes in Northwestern Pacific Volcanic Regions
Quick Info
- •Smithsonian ID: 284132
- •Evidence: Unrest / Holocene
- •Epoch: Holocene
About the Photo
Two large cones have been constructed on the NW and NE rims of a roughly 3-km-wide submarine caldera at Nikko. The caldera rim is prominently displayed on the southern side and is largely buried to the north. A smaller cone fomed on the SE caldera floor. Discolored water has frequently been observed above the seamount and hydrothermal venting was documented at the main cone during a NOAA expedition.
Image courtesy of NOAA, 2003 (http://oceanexplorer.noaa.gov/explorations/03fire/logs/mar02/media/nikko.html).
Authority Sources
Related Volcanoes
Basic Information
This page shows basic data from the Smithsonian Global Volcanism Program. For more detailed information, visit the official Smithsonian page.