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Yantarni

Stratovolcano in United States

Last Eruption: -800

Key Facts

Elevation

1,345 m (4,413 ft)

Type

Stratovolcano

Location

57.019°, -157.185°

Region

Alaska Peninsula Volcanic Arc

Rock Type

Andesite / Basaltic Andesite

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

Yantarni is a small andesitic stratovolcano located between Aniakchak caldera and Chiginadak volcanoes that was not discovered until 1979. A large breached crater on the NE side, formed by collapse of the summit about 2000-3500 years ago, contains a lava dome that marks the summit. This eruption, which resembled that of Mount St.

Helens in 1980, began with a debris avalanche produced by the edifice collapse that was accompanied by a possible lateral blast and followed by the emplacement of 1 km3 of pyroclastic flows related to growth of the summit lava dome.

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 Dated

Eruption Statistics & Analysis

MetricValueGlobal RankingSignificance
Total Recorded EruptionsUnknownLowModerately active volcano
Maximum VEIVEI UnknownMinorLocal impact potential
Recent Activity2826 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 North America Volcanic Regions

Regional Volcanic Activity
The North America 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: 312100
  • Evidence: Eruption Dated
  • Epoch: Holocene

About the Photo

Yantarni is located on the Alaska Peninsula, with this view from the east showing the lava dome at the summit. On either side of the dome are remnants of a large crater that opens to the NE, which formed during flank collapse about 2,000-3,500 years ago.

Photo by Tom Miller, 1985 (Alaska Volcano Observatory, 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.