Makushin
Stratovolcano in United States
Key Facts
Elevation
1,800 m (5,906 ft)
Type
Stratovolcano
Location
53.891°, -166.923°
Region
Aleutian Ridge Volcanic Arc
Rock Type
Andesite / Basaltic Andesite
Tectonic Setting
Subduction zone
Location
Loading map...
Overview
The ice-covered Makushin volcano on northern Unalaska Island is capped by a 2. 5 km caldera. Its broad, dome-like structure contrasts with the steep-sided profiles of most other Aleutian stratovolcanoes.
Much of the edifice was formed during the Pleistocene, but the caldera (which formed about 8,000 years ago), Sugarloaf cone on the ENE flank, and a cluster of about a dozen explosion pits and cinder cones at Point Kadin on the WNW flank, are of Holocene age. A broad band of NE-SW-trending vents cuts across the volcano. The composite Pakushin cone, with multiple summit craters, lies 8 km SW.
Table Top (Pleistocene, 68 +/- 14 ka) and Wide Bay (Holocene) cinder cones are about 20 km ENE on the peninsula across the bay from the City of Unalaska. Frequent explosive eruptions have occurred during the past 4,000 years, sometimes accompanied by pyroclastic flows and surges. Geothermal areas are found in the summit caldera and on the SE and E flanks.
Small-to-moderate explosive eruptions have been recorded since 1786.
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 | 31 years ago | Recent | Recently active |
Monitoring & Alert Status
Monitoring Networks
Current Status
Nearby Volcanoes in North America Volcanic Regions
Quick Info
- •Smithsonian ID: 311310
- •Evidence: Eruption Observed
- •Epoch: Holocene
About the Photo
Makushin is a glaciated volcano on northern Unalaska Island. This 2 March 1987 view from the NE shows a small plume originating from a vent on the left side of the broad summit and drifting about 3 km WNW. The summit contains a 2-km-wide caldera. Minor explosive eruptions have occurred during historical time.
Photo by Harold Wilson (Peninsula Airways), 1987 (courtesy of John Reeder, Alaska Div. Geology Geophysical Surveys).
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.