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Miravalles

Stratovolcano in Costa Rica

Last Eruption: 1946

Key Facts

Elevation

2,028 m (6,654 ft)

Type

Stratovolcano

Location

10.748°, -85.153°

Region

Central America Volcanic Arc

Rock Type

Andesite / Basaltic Andesite

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

Miravalles is an andesitic stratovolcano that is one of five post-caldera cones along a NE-trending line within the broad 15 x 20 km Guayabo (Miravalles) caldera. The caldera was formed during several major explosive eruptions that produced voluminous dacitic-rhyolitic pyroclastic flows between ~1. 5 and 0.

6 million years ago. Growth of post-caldera volcanoes in the eastern part of the caldera that overtopped much of the eastern and southern caldera rims was interrupted by edifice collapse which produced a major debris avalanche to the SW. Morphologically youthful lava flows cover the W and SW flanks of the post-caldera Miravalles complex, which rises above the town of Guayabo on the flat western caldera floor.

A small steam explosion on the SW flank was reported in 1946. High heat flow remains, and it is the site of a large developed geothermal field.

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 Activity80 years agoHistoricalRecently active

Monitoring & Alert Status

Monitoring Networks

Global Volcanism Program
International eruption database

Current Status

Normal
No recent activity. Routine monitoring continues.

Nearby Volcanoes in Middle America-Caribbean Volcanic Regions

Regional Volcanic Activity
The Middle America-Caribbean 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: 345030
  • Evidence: Eruption Observed
  • Epoch: Holocene

About the Photo

A geothermal area is seen here on the Miravalles SW flank in 1988. The edifice is one of five post-caldera cones constructed within the Pleistocene Guayabo caldera. Lava flows cover the W and SW flanks. A small steam explosion was reported in 1946 and a producing geothermal field is located within the caldera.

Photo by William Melson, 1988 (Smithsonian Institution)

Basic Information

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