Ushishur
Caldera in Russia
Key Facts
Elevation
357 m (1,171 ft)
Type
Caldera
Location
47.513°, 152.814°
Region
Kuril Volcanic Arc
Rock Type
Andesite / Basaltic Andesite
Tectonic Setting
Subduction zone
Location
Loading map...
Overview
The subaerial portion of Ushishur volcano in the central Kuriles is exposed in two small islands, the southern containing the summit caldera and the northern a portion of the volcano's flanks. A small 1. 6-km-wide caldera that formed about 9,400 years ago is narrowly breached on the south, allowing seawater to fill the caldera.
Two andesitic lava domes occupy part of the caldera bay; two other older domes are joined by a sand bar to the SE caldera wall. The two younger domes, erupted sometime after the 1769 visit of Captain Snow, form islands in the bay. A cluster of strong fumaroles and hot springs are present along the SE caldera shoreline, and vigorous submarine hydrothermal activity has modified the geochemistry of water within the caldera bay.
Aside from growth of the two younger lava domes, only minor phreatic eruptions have been recorded.
Volcanic Hazards & Risk Assessment
Primary Hazards
- Pyroclastic flows and surges
- Large explosive eruptions (VEI 4+)
- Ash fall and tephra deposits
- Lahars and debris flows
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 | 142 years ago | Historical | Historically active |
Monitoring & Alert Status
Monitoring Networks
Current Status
Nearby Volcanoes in Northwestern Pacific Volcanic Regions
Quick Info
- •Smithsonian ID: 290210
- •Evidence: Eruption Observed
- •Epoch: Holocene
About the Photo
The 1.6-km-wide caldera of Ushishur volcano opens towards the south and formed during an eruption about 9,400 years ago. Two post-caldera lava domes that erupted sometime after a 1769 visit of Captain Snow form islands in the caldera bay. Two older domes in front of the islands are joined by a sand bar to the SE caldera wall. A northern island (top) consists of a portion of the flanks.
Photo by R. Bulgakov, 1990 (Institute of Marine Geology and Geophysics, Yuzhno-Sakhalin).
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.