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Asuncion

Stratovolcano in United States

Last Eruption: 1906

Key Facts

Elevation

857 m (2,812 ft)

Type

Stratovolcano

Location

19.671°, 145.406°

Region

Mariana Volcanic Arc

Rock Type

Andesite / Basaltic Andesite

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

A single large asymmetrical stratovolcano forms 3-km-wide Asuncion Island. The steeper NE flank terminates in high sea cliffs, while the gentler SW flanks have low-angle slopes bounded by sea cliffs only a few meters high. The southern flank is cut by a large landslide scar.

The S and W flanks are covered by ash deposits. An explosive eruption in 1906 produced lava flows that descended about halfway down the W and SE flanks, but several other eruption reports are of uncertain validity.

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 Activity120 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: 284150
  • Evidence: Eruption Observed
  • Epoch: Holocene

About the Photo

An aerial view from the SW shows the upper slopes of Asuncion in the northern Mariana Islands. It forms a circular 3-km-wide island that has had no permanent residents since the late 17th century. An explosive eruption in 1906 produced lava flows that descended about halfway down the W and S flanks.

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.