Ritter Island
Stratovolcano in Papua New Guinea
Key Facts
Elevation
75 m (246 ft)
Type
Stratovolcano
Location
-5.519°, 148.115°
Region
Bismarck Volcanic Arc
Rock Type
Basalt / Picro-Basalt
Tectonic Setting
Subduction zone
Location
Loading map...
Overview
Prior to 1888, Ritter Island was a steep-sided, nearly circular island about 780 m high between Umboi and Sakar Islands. Several historical explosive eruptions had been recorded prior to 1888, when large-scale slope failure destroyed the summit of the conical basaltic-andesitic volcano, leaving the arcuate 140-m-high island with a steep west-facing scarp. Devastating tsunamis were produced by the collapse and swept the coast of Papua New Guinea and offshore islands.
Two minor post-collapse explosive eruptions, during 1972 and 1974, occurred offshore within the largely submarine 3. 5 x 4. 5 km breached depression formed by the collapse.
Volcanic Hazards & Risk Assessment
Primary Hazards
- Pyroclastic flows
- Lava flows
- Volcanic bombs and ballistics
- Lahars and mudflows
Risk Level
Geological Composition & Structure
Rock Types
Tectonic Setting
Age & Formation
Eruption Statistics & Analysis
| Metric | Value | Global Ranking | Significance |
|---|---|---|---|
| Total Recorded Eruptions | Unknown | Low | Moderately active volcano |
| Maximum VEI | VEI Unknown | Minor | Local impact potential |
| Recent Activity | 19 years ago | Recent | Recently active |
Monitoring & Alert Status
Monitoring Networks
Current Status
Nearby Volcanoes in Southwestern Pacific Volcanic Regions
Quick Info
- •Smithsonian ID: 251070
- •Evidence: Eruption Observed
- •Epoch: Holocene
About the Photo
This arcuate, 1.9-km-long, 200-m-wide island is what remains of Ritter Island after its collapse in 1888. Prior to 1888 this was a steep-sided nearly circular island about 780 m high. Large-scale slope failure removed the summit of the conical volcano, leaving an arcuate 140-m-high west-facing scarp, seen here from the SW. Two minor post-collapse explosive eruptions occurred offshore during 1972 and 1974.
Photo by Wally Johnson, 1974 (Australia Bureau of Mineral Resources).
Authority Sources
Related Volcanoes
Basic Information
This page shows basic data from the Smithsonian Global Volcanism Program. For more detailed information, visit the official Smithsonian page.