🌋VolcanoAtlas

Bobrof

Stratovolcano in United States

Key Facts

Elevation

738 m (2,421 ft)

Type

Stratovolcano

Location

51.910°, -177.438°

Region

Aleutian Ridge Volcanic Arc

Rock Type

Basalt / Picro-Basalt

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

The geology and timing of volcanism on this small uninhabited 3 x 4 km island, located in the Andreanof islands 50 km west of Adak and 15 km west of Kanaga volcano, are unknown (Coats, 1956). Apparent deposits of a massive submarine debris-avalanche deposit extend offshore to the NE. Smith et al.

(1978) considered Bobrof to be of possible Holocene age. Andesitic pyroclastic-flow deposits are present on the 738-m-high volcano.

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
Basalt / Picro-Basalt
Silica Content
Low (45-52% 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 Uncertain

Eruption Statistics & Analysis

MetricValueGlobal RankingSignificance
Total Recorded EruptionsUnknownLowModerately active volcano
Maximum VEIVEI UnknownMinorLocal impact potential
Recent ActivityUnknownHistoricalHistorically 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: 311100
  • Evidence: Evidence Uncertain
  • Epoch: Holocene

About the Photo

The small 3 x 4 km Bobrof volcanic island lies 50 km W of Adak and 15 km W of Kanaga volcano. The irregular shoreline has a half-dozen small cliff-bound peninsulas. The geology and timing of volcanism on Bobrof are unknown, but pyroclastic flow deposits are present.

Photo courtesy of 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.