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Shasta

Stratovolcano in United States

Last Eruption: 1250

Key Facts

Elevation

4,317 m (14,163 ft)

Type

Stratovolcano

Location

41.409°, -122.193°

Region

High Cascades Volcanic Arc

Rock Type

Andesite / Basaltic Andesite

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

The most voluminous of the Cascade volcanoes, northern California's Mount Shasta is a massive compound stratovolcano composed of at least four main edifices constructed over a period of at least 590,000 years. An older edifice was destroyed by a large debris avalanche which filled the Shasta River valley to the NW. The Hotlum cone, forming the present summit, the Shastina lava dome complex, and the SW flank Black Butte lava dome, were constructed during the early Holocene.

Eruptions from these vents have produced pyroclastic flows and mudflows that affected areas as far as 20 km from the summit. Eruptions from Hotlum cone continued throughout the Holocene.

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 Activity776 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: 323010
  • Evidence: Eruption Observed
  • Epoch: Holocene

About the Photo

Mount Shasta in northern California, seen here from the SE, is one of the largest of the Cascades volcanoes and is constructed of at least four overlapping edifices. Hotlum cone (forming the summit), along with the Shastina and Black Buttes lava domes, were all constructed during the Holocene.

Photo by Lyn Topinka, 1984 (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.