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Amak

Stratovolcano in United States

Last Eruption: 1796

Key Facts

Elevation

547 m (1,795 ft)

Type

Stratovolcano

Location

55.418°, -163.147°

Region

Aleutian Ridge Volcanic Arc

Rock Type

Andesite / Basaltic Andesite

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

Amak, the easternmost of the Aleutian Islands, is a small island stratovolcano that lies north of the main Aleutian volcanic front, about 50 km NW of Frosty volcano on the western tip of the Alaska Peninsula. The summit of the small, roughly 1 km3 volcano is only 488 m above sea level. Blocky lava flows with prominent levees were emplaced during historical eruptions from 1700-1710 and in 1796 (Marsh, in Wood and Kienle 1990).

The flows radiate from a well-defined central crater and cover much of the central part of the island. Earlier volcanism perhaps 4000-5000 years ago consisted of the emission of thin, platy andesitic lava flows. A flat alluvial plain on the S flank contains a flat-bottomed crater that may be a maar.

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 Observed

Eruption Statistics & Analysis

MetricValueGlobal RankingSignificance
Total Recorded EruptionsUnknownLowModerately active volcano
Maximum VEIVEI UnknownMinorLocal impact potential
Recent Activity230 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: 311390
  • Evidence: Eruption Observed
  • Epoch: Holocene

About the Photo

Amak, the easternmost of the Aleutian Islands, lies north of the tip of the Alaskan Peninsula. Like Bogoslof, it lies north of the main Aleutian volcanic front. Lava flows with prominent levees were emplaced in historical eruptions during 1700-1710 and in 1796.

Photo by Dave Roseneau, 2001 (U.S. Fish and Wildlife Service).

Basic Information

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