🌋VolcanoAtlas

Spurr

Stratovolcano in United States

Last Eruption: 1992

Key Facts

Elevation

3,374 m (11,070 ft)

Type

Stratovolcano

Location

61.299°, -152.251°

Region

Alaska Peninsula Volcanic Arc

Rock Type

Andesite / Basaltic Andesite

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

Mount Spurr is the closest volcano to Anchorage, Alaska (130 km W) and just NE of Chakachamna Lake. The summit is a large lava dome at the center of a roughly 5-km-wide amphitheater open to the south formed by a late-Pleistocene or early Holocene debris avalanche and associated pyroclastic flows that destroyed an older edifice. The debris avalanche traveled more than 25 km SE, and the resulting deposit contains blocks as large as 100 m in diameter.

Several ice-carved post-collapse cones or lava domes are present. The youngest vent, Crater Peak, formed at the southern end of the amphitheater and has been the source of about 40 identified Holocene tephra layers. Eruptions from Crater Peak in 1953 and 1992 deposited ash in Anchorage.

Volcanic Hazards & Risk Assessment

Primary Hazards

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

Risk Level

Population at RiskModerate
Infrastructure RiskHigh
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 Activity34 years agoRecentRecently active

Monitoring & Alert Status

Monitoring Networks

Global Volcanism Program
International eruption database

Current Status

Watch
Dormant but monitored. Capable of renewed activity.

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: 313040
  • Evidence: Eruption Observed
  • Epoch: Holocene

About the Photo

During the late Pleistocene or early Holocene Mount Spurr underwent flank collapse, resulting in the 5-6 km crater that opens to the south shown here in 1993. The collapse produced a debris avalanche that traveled at least 25 km from the summit. The snow-covered peak (center) is a post-collapse lava dome. Crater Peak, in front of it, has been the source of frequent Holocene eruptions.

Photo by Christina Neal, 1993 (U.S. Geological Survey, Alaska Volcano Observatory).

Basic Information

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