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Moffett

Stratovolcano in United States

Last Eruption: -1600

Key Facts

Elevation

1,196 m (3,924 ft)

Type

Stratovolcano

Location

51.944°, -176.747°

Region

Aleutian Ridge Volcanic Arc

Rock Type

Andesite / Basaltic Andesite

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

Rising above Adak, the largest town of the Aleutians, Mount Moffett is a modest-sized, eroded stratovolcano with several flank lava domes. The summit cone has been largely destroyed by glacial erosion, and has been filled by an andesitic plug dome. Five other lava domes are scattered over the flanks of the volcano.

The south flank lava dome is one of the youngest features of the northern Adak Island volcanoes. The Heart Lake lava flow west of Sweeper Cove on the SE side of the volcano is another young volcanic feature. Several Holocene ash layers on Adak Island have been attributed to Moffett volcano.

Its proximity to Adak Naval Air Station makes this one of the most accessible of the Aleutian volcanoes. Kiguga Warm Springs are located at Cape Kiguga, west of Mount Moffet, and the northern part of Adak Island has been investigated for geothermal power production.

Volcanic Hazards & Risk Assessment

Primary Hazards

  • Pyroclastic flows
  • Lava flows
  • Volcanic bombs and ballistics
  • Lahars and mudflows

Risk Level

Population at RiskModerate
Infrastructure RiskModerate
Aviation RiskSignificant

Geological Composition & Structure

Rock Types

Primary
Andesite / Basaltic Andesite
Silica Content
Intermediate (57-63% SiO₂)

Tectonic Setting

Subduction zone
Formed by oceanic plate subduction, typically producing explosive eruptions due to water-rich magmas.

Age & Formation

Epoch
Holocene
Evidence
Eruption Dated

Eruption Statistics & Analysis

MetricValueGlobal RankingSignificance
Total Recorded EruptionsUnknownLowModerately active volcano
Maximum VEIVEI UnknownMinorLocal impact potential
Recent Activity3626 years agoHistoricalHistorically active

Monitoring & Alert Status

Monitoring Networks

Global Volcanism Program
International eruption database

Current Status

Normal
No recent activity. Routine monitoring continues.

Nearby Volcanoes in North America Volcanic Regions

Regional Volcanic Activity
The North America Volcanic Regions contains multiple active volcanic systems. Cross-regional magma interactions and tectonic stresses can influence eruption patterns across the entire arc. Monitor regional seismic activity and volcanic alerts.

Quick Info

  • Smithsonian ID: 311111
  • Evidence: Eruption Dated
  • Epoch: Holocene

About the Photo

Mount Moffett has several flank lava domes and is seen here across Andrew Bay to the SW from Mount Adagdak. Andrew Bay volcano is the oldest of three volcanic centers on northern Adak Island. Mount Moffett rises above Adak (out of view to the left), the largest town of the Aleutians.

Photo courtesy of Alaska Volcano Observatory, U.S. Geological Survey.

Basic Information

This page shows basic data from the Smithsonian Global Volcanism Program. For more detailed information, visit the official Smithsonian page.