Irruputuncu

Stratovolcano in Chile-Bolivia

Last Eruption: 1995

Key Facts

Elevation

5,163 m (16,939 ft)

Type

Stratovolcano

Location

-20.730°, -68.550°

Region

Central Andean Volcanic Arc

Rock Type

Andesite / Basaltic Andesite

Tectonic Setting

Subduction zone

Location

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Overview

Irruputuncu is a small stratovolcano that straddles the Chile/Bolivia border. It is the youngest and most southerly of a NE-SW-trending chain of volcanoes. It was constructed within the collapse scarp of a Holocene debris avalanche whose deposit extends to the SW.

Subsequent eruptions filled much of this scarp and produced thick, viscous lava flows down the W flank. The summit complex contains two craters, the southernmost of which is fumarolically active. The first unambiguous historical eruption took place in November 1995, when phreatic explosions produced dark ash clouds.

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

Metric	Value	Global Ranking	Significance
Total Recorded Eruptions	Unknown	Low	Moderately active volcano
Maximum VEI	VEI Unknown	Minor	Local impact potential
Recent Activity	31 years ago	Recent	Recently 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 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: 355040
•Evidence: Eruption Observed
•Epoch: Holocene

About the Photo

Steam rises from the fumarolically active southern summit crater of Irruputuncu, a small stratovolcano that straddles the Chile/Bolivia border. Irruputuncu, seen here from the WSW, was constructed within the collapse scarp of a Holocene debris avalanche whose deposit extends to the SW. Levees of viscous lava flows down the western flank of an edifice that was constructed within this scarp are seen at the lower left. The first unambiguous historical eruption from Irruputuncu took place in November 1995.

Photo by José Naranjo, 2001 (Servico Nacional de Geologica y Mineria).