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Cosiguina

Stratovolcano in Nicaragua

Last Eruption: 1859

Key Facts

Elevation

872 m (2,861 ft)

Type

Stratovolcano

Location

12.980°, -87.570°

Region

Central America Volcanic Arc

Rock Type

Andesite / Basaltic Andesite

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

Cosigüina (also spelled Cosegüina) is a low basaltic-to-andesitic composite volcano that is isolated from other eruptive centers in the Nicaraguan volcanic chain. The stratovolcano forms a large peninsula extending into the Gulf of Fonseca at the western tip of the country. It has a pronounced somma rim on the northern side; a young summit cone rises 300 m above the northern somma rim and buries the rim on other sides.

The younger cone is truncated by a large elliptical prehistorical summit caldera, 2 x 2. 4 km in diameter and 500 m deep, with a lake at its bottom. Lava flows predominate in the caldera walls, although lahar and pyroclastic-flow deposits surround the volcano.

A brief but powerful explosive eruption in 1835 is Nicaragua's largest during historical time. Ash fell as far away as México, Costa Rica, and Jamaica, and pyroclastic flows reached the Gulf of Fonseca.

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
Eruption Observed

Eruption Statistics & Analysis

MetricValueGlobal RankingSignificance
Total Recorded EruptionsUnknownLowModerately active volcano
Maximum VEIVEI UnknownMinorLocal impact potential
Recent Activity167 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 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: 344010
  • Evidence: Eruption Observed
  • Epoch: Holocene

About the Photo

Cosigüina, seen here from the east, is a low basaltic-to-andesitic composite volcano that forms a large peninsula at the NW tip of Nicaragua along the Gulf of Fonseca. The 872-m-high volcano has a pronounced somma rim, which forms the ridge seen here at the right behind the far crater rim. The younger cone is truncated by a large elliptical prehistorical summit caldera 2 x 2.4 km in diameter and 500 m deep, which is now filled by a lake. It was the source of a major explosive eruption in 1835, Nicaragua's largest during historical time.

Photo by Jaime Incer, 1981.

Basic Information

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