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Chagulak

Stratovolcano in United States

Key Facts

Elevation

1,028 m (3,373 ft)

Type

Stratovolcano

Location

52.572°, -171.138°

Region

Aleutian Ridge Volcanic Arc

Rock Type

Andesite / Basaltic Andesite

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

The 3-km-diameter island of Chagulak is the exposed summit of a stratovolcano in the Islands of the Four Mountains group of the Aleutians. The sharp-topped summit is ~11 km NE of the summit of Amukta and 35 km W of Yunaska volcano. The visible edifice is steep and strongly eroded.

No eruptions have been recorded and its age is not precisely known.

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
Evidence Uncertain

Eruption Statistics & Analysis

MetricValueGlobal RankingSignificance
Total Recorded EruptionsUnknownLowModerately active volcano
Maximum VEIVEI UnknownMinorLocal impact potential
Recent ActivityUnknownHistoricalHistorically 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: 311200
  • Evidence: Evidence Uncertain
  • Epoch: Holocene

About the Photo

The eastern side of the Chagulak volcano is seen here in the foreground and Amukta is in the background. The two volcanoes join at depth but at the surface they are separated by 7 km of ocean.

Photo by Fred Deines, 1992 (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.