🌋VolcanoAtlas

Guguan

Stratovolcano in United States

Last Eruption: 1883

Key Facts

Elevation

232 m (761 ft)

Type

Stratovolcano

Location

17.314°, 145.840°

Region

Mariana Volcanic Arc

Rock Type

Andesite / Basaltic Andesite

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

The island of Guguan, ~2. 8 km in diameter, is composed of an eroded volcano on the south, a caldera with a post-caldera cone, and a northern volcano. The latter has three coalescing cones and a breached summit crater that fed lava flows to the W and NW.

The only known reported eruption, between 1882 and 1884, produced the northern volcano and lava flows that reached the coast. Freycinet (Uranie 1817 Expedition) confused Guguan and Alamagan; reported eruptions in 1819 and 1901 (Kuno, 1962 CAVW) actually refer to solfataric activity on Alamagan (Corwin, 1971).

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 Activity143 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 Northwestern Pacific Volcanic Regions

Regional Volcanic Activity
The Northwestern Pacific 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: 284190
  • Evidence: Eruption Observed
  • Epoch: Holocene

About the Photo

The 2.8-km-wide Guguan island in the central Marianas Islands, seen here from the NW, is composed of an eroded volcano at the south and a caldera with a post-caldera cone. The northern cone (foreground) was the site of an eruption in the 19th century. It has three coalescing cones and a summit crater that produced lava flows to the W and NW.

Photo by Richard Moore, 1992 (U.S. Geological Survey).

Basic Information

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