Cay

Stratovolcano in Chile

Key Facts

Elevation

2,090 m (6,857 ft)

Type

Stratovolcano

Location

-45.059°, -72.984°

Region

Southern Andean Volcanic Arc

Rock Type

Andesite / Basaltic Andesite

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

Volcán Cay, located E of Macá volcano and NW of the town of Puerto Aisén, is a basaltic to dacitic stratovolcano. An explosion crater is open to the E, and about a half dozen explosion craters and pyroclastic cones lie along a fissure trending SW of the summit. Another 10 basaltic pyroclastic cones are located along a second parallel fissure 5 km SE that is part of the major regional Liquiñe-Ofqui fault zone.

These cones were considered to be Holocene by González-Ferrán (1995), but Naranjo and Stern (2004) found no evidence for Holocene tephra deposits.

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

Metric	Value	Global Ranking	Significance
Total Recorded Eruptions	Unknown	Low	Moderately active volcano
Maximum VEI	VEI Unknown	Minor	Local impact potential
Recent Activity	Unknown	Historical	Historically 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: 358055
•Evidence: Evidence Uncertain
•Epoch: Holocene

About the Photo

Volcán Cay (upper left), is located east of Macá volcano (lower right) and NW of the town of Puerto Aisén. The basaltic and dacitic stratovolcano has an explosion crater that is open to the east, and about a half dozen explosion craters and pyroclastic cones lie along a fissure trending SW of the summit. Another 10 basaltic pyroclastic cones are located along second parallel fissure 5 km to the SE that is part of the major regional Liquiñe-Ofqui fault zone.

Photo by Oscar González-Ferrán (University of Chile).