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Osorno

Stratovolcano in Chile

Last Eruption: 1869

Key Facts

Elevation

2,659 m (8,724 ft)

Type

Stratovolcano

Location

-41.105°, -72.496°

Region

Southern Andean Volcanic Arc

Rock Type

Basalt / Picro-Basalt

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

The symmetrical, glaciated, Osorno volcano towers above Todos los Santos and Llanquihué lakes. It was constructed over the SW part of a roughly 250,000-year-old eroded stratovolcano, La Picada, that has a mostly buried 6-km-wide caldera. The dominantly basaltic to basaltic andesite volcano includes two small dacitic lava domes on the NW and SSE flanks.

Flank scoria cones and fissure vents, primarily on the W and SW sides, have produced lava flows that reached Lago Llanquihué. Frequent explosive eruptions including pyroclastic flows and surges have occurred during the past 14,000 years. Recorded eruptions have originated from summit and flank vents, producing basaltic and andesitic lava flows that have entered both Llanquihué and Todos los Santos lakes.

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
Basalt / Picro-Basalt
Silica Content
Low (45-52% 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 Activity157 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 South America Volcanic Regions

Regional Volcanic Activity
The South 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: 358010
  • Evidence: Eruption Observed
  • Epoch: Holocene

About the Photo

The symmetrical, glacier-clad Osorno stratovolcano forms a renowned landmark between Todos Los Santos and Llanguihue lakes. It is seen here from the north, with Calbuco volcano visible at the extreme right. The 2652-m-high Osorno is one of the most active volcanoes of the southern Chilean Andes. Flank scoria cones and fissure vents, primarily on the west and SW sides, have produced lava flows that reached Lago Llanguihue. Historical eruptions have originated from both summit and flank vents.

Photo by Hugo Moreno (University of Chile).

Basic Information

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