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Kasuga 2

Stratovolcano in United States

Key Facts

Elevation

-274 m (-899 ft)

Type

Stratovolcano

Location

21.600°, 143.637°

Region

Mariana Volcanic Arc

Rock Type

Basalt / Picro-Basalt

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

Kasuga 2, also referred to as Minami Kasuga (South Kasuga), is the central of three volcanoes forming the Kasuga seamount chain, which trends SSW from the volcanic front of the Izu-Marianas arc. It rises from about 3,000 m depth to within 170 m of the ocean surface. Two subsidiary cones are located low on the E flank.

The morphology is more complex than Kasuga 1 to the north, and prominent ridges separate slopes of interspersed volcaniclastic and lava flow fields. Radiometric dating indicates an age of less than 8,000 years and probably less than 1,000 years; radium/thorium disequilibrium ratios suggest the flows may be only a few centuries old (Fryer et al. , 1997).

Active hydrothermal vents are located at the summit, at the base of summit ridges, and on the lower flanks.

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 Credible

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 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: 284135
  • Evidence: Evidence Credible
  • Epoch: Holocene

About the Photo

Minami Kasuga (South Kasuga) submarine volcano is seen in this bathymetric image, looking from the SW with 2x vertical exaggeration. Bathymetic contours are overlain on SeaBat data courtesy of Koichi Nakamura (National Institute of Advanced Science and Technology, Japan). It rises from about 3,000 m depth to within about 170 m of the sea surface. Two smaller cones are located low on the eastern flank. Active hydrothermal fields are located at the summit of and lower flanks.

Image courtesy of NOAA vents program, 2006 (http://oceanexplorer.noaa.gov/explorations/06fire).

Basic Information

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