Edgecumbe
Volcanic field in United States
Key Facts
Elevation
970 m (3,182 ft)
Type
Volcanic field
Location
57.050°, -135.750°
Region
Queen Charlotte Volcano Group
Rock Type
Andesite / Basaltic Andesite
Tectonic Setting
Intraplate
Location
Loading map...
Overview
The Edgecumbe volcanic field covers about 260 km2 of Kruzov Island west of Sitka in SE Alaska. The basaltic-to-dacitic field is dominated by the large composite cones of Mount Edgecumbe, Crater Ridge, and Shell Mountain. This Pleistocene-to-Holocene system is 16 km E of the Queen Charlotte-Fairweather transform fault separating the North American and Pacific plates.
Mount Edgecumbe is a stratovolcano with a well-defined crater, and is the largest edifice of the field. Crater Ridge is truncated by a 1. 6-km-wide, 240-m-deep caldera.
These and other vents are oriented along a SW-NE line. Volcanic activity originated about 600,000 years ago along fissures cutting Kruzof Island. A series of major silicic explosive eruptions took place about 9,000-13,000 radiocarbon years ago.
The latest dated eruptions were phreatomagmatic explosions during the mid-Holocene, and all postglacial activity has been pyroclastic. Reports of observed eruptions are unsubstantiated.
Volcanic Hazards & Risk Assessment
Primary Hazards
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 | 4106 years ago | Historical | Historically active |
Monitoring & Alert Status
Monitoring Networks
Current Status
Nearby Volcanoes in North America Volcanic Regions
Quick Info
- •Smithsonian ID: 315040
- •Evidence: Eruption Dated
- •Epoch: Holocene
About the Photo
The Pleistocene-to-Holocene Mount Edgecumbe volcanic field covers about 260 km2 of Kruzov Island west of Sitka in the SE panhandle of Alaska. This aerial view shows oxidized scoria of the Edgecumbe volcano in the foreground. Crater Ridge in the background contains a 1.6-km-wide, 240-m deep caldera. And rhyolite domes (top right) The youngest eruptions from Mount Edgecumbe, the largest feature in the Edgecumbe field, are about 4,000 years old.
Photo by Jim Riehle (U.S. Geological Survey, Alaska Volcano Observatory).
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.