Katmai
Stratovolcano in United States
Key Facts
Elevation
2,047 m (6,716 ft)
Type
Stratovolcano
Location
58.279°, -154.953°
Region
Alaska Peninsula Volcanic Arc
Rock Type
Andesite / Basaltic Andesite
Tectonic Setting
Subduction zone
Location
Loading map...
Overview
Katmai was initially considered to be the source of the Valley of Ten Thousand Smokes ash flow in 1912. However, the 3 x 4 km caldera of 1912 is now known to have formed as a result of the voluminous eruption at nearby Novarupta volcano. The edifice had four NE-SW-trending summits, most of which were truncated by the 1912 collapse.
Two or more large explosive eruptions took place during the late Pleistocene. Most of the two overlapping pre-1912 Katmai volcanoes are Pleistocene, but Holocene lava flows from a flank vent descend the SE flank of the SW edifice into the Katmai River canyon. The steep walled young caldera has a jagged rim that rises 500-1,000 m above the caldera floor and contains a deep lake.
Lake waters have covered a small post-collapse lava dome (Horseshoe Island) that was seen on the caldera floor at the time of the initial ascent to the caldera rim in 1916.
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 | 114 years ago | Historical | Historically active |
Monitoring & Alert Status
Monitoring Networks
Current Status
Nearby Volcanoes in North America Volcanic Regions
Quick Info
- •Smithsonian ID: 312170
- •Evidence: Eruption Observed
- •Epoch: Holocene
About the Photo
Katmai caldera, formed during the catastrophic eruption of the nearby Novarupta vent in June 1912, is seen here in an aerial view from the NE. The steep-walled, 1.5-km-wide caldera formed on a cluster of overlapping cones and is partially filled by a lake. Beyond the caldera are the multiple peaks of Trident volcano; Mageik volcano is the snow-and-ice-covered cone in the background.
Photo by Chris Nye, 1991 (Alaska Division of Geological and Geophysical Surveys, 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.