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Coatepeque Caldera

Caldera in El Salvador

Key Facts

Elevation

746 m (2,448 ft)

Type

Caldera

Location

13.870°, -89.550°

Region

Central America Volcanic Arc

Rock Type

Rhyolite

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

Coatepeque is a 6. 5 x 11. 5 km collapse caldera ~50 km W of San Salvador that is largely occupied by a lake with hot springs near the margins.

The height of the caldera rim increases on its W side, where it intersects the E flank of Santa Ana. The caldera was formed during a series of major rhyolitic explosive eruptions between ~72,000 and 51,000 years ago. Post-caldera eruptions included the formation of basaltic cinder cones and lava flows near the western margin of the caldera and the extrusion of rhyodacitic lava domes along a NE-SW line near the caldera lake margins.

The highest dome forms Isla de Cabra, or Cerro Grande. The age of the domes is not known precisely, but the youngest dome, Cerro Pacho, was estimated to have formed less than 10,000 years ago. No verified eruptions have been recorded.

Volcanic Hazards & Risk Assessment

Primary Hazards

  • Pyroclastic flows and surges
  • Large explosive eruptions (VEI 4+)
  • Ash fall and tephra deposits
  • Lahars and debris flows

Risk Level

Population at RiskModerate
Infrastructure RiskModerate
Aviation RiskSignificant

Geological Composition & Structure

Rock Types

Primary
Rhyolite
Silica Content
High (>68% 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 Credible

Eruption Statistics & Analysis

MetricValueGlobal RankingSignificance
Total Recorded EruptionsUnknownLowModerately active volcano
Maximum VEIVEI UnknownMinorLocal impact potential

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: 343041
  • Evidence: Evidence Credible
  • Epoch: Holocene

About the Photo

The 7 x 10 km Coatepeque caldera is seen here from the Santa Ana summit. The caldera formed during a series of major explosive eruptions between about 70,000 and 57,000 years ago. Post-caldera eruptions included the formation of basaltic scoria cones and lava flows near the western margin of the caldera and the extrusion of lava domes, including Cerro Grande, the island in the W side of the caldera lake.

Photo by Lee Siebert, 2002 (Smithsonian Institution).

Basic Information

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