Sessagara Hills
Volcanic field in Papua New Guinea
Key Facts
Elevation
493 m (1,617 ft)
Type
Volcanic field
Location
-9.554°, 149.128°
Region
Trobriand Volcanic Province
Rock Type
Trachyandesite / Basaltic Trachyandesite
Tectonic Setting
Subduction zone
Location
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Overview
The small low-lying andesitic Sessagara Hills volcanic field is located near the mouth of the Uiaka River, south of Collingwood Bay and NE of the Goropu Mountains on the Papuan Peninsula of New Guinea. There are at least two small forest-covered cones, with a small cone and obvious crater ~5 km NE of them and the Waiowa cone ~6 km W. Besides Waiowa (also known as Goropu), Smith (1981) considered some other features in the field to be Holocene; other cones may be of Pleistocene age.
The Waiowa pyroclastic cone was formed during 1943-44 by explosive eruptions through Paleozoic to Precambrian metamorphic rocks. Intermittent minor explosions beginning on 18 September 1943 preceded the first major explosion on 27 December. Additional large explosions occurred on 13 February and 23 July 1944, leveling 80 km2 of forest.
Following the final activity on 31 August, the small cone included a 500-m-wide, steep-walled crater that later became densely forested and contains a small lake.
Volcanic Hazards & Risk Assessment
Primary Hazards
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 | 82 years ago | Historical | Recently active |
Monitoring & Alert Status
Monitoring Networks
Current Status
Nearby Volcanoes in Southwestern Pacific Volcanic Regions
Quick Info
- •Smithsonian ID: 253040
- •Evidence: Eruption Observed
- •Epoch: Holocene
About the Photo
Waiowa (also known as Goropu) is an isolated tuff cone that was formed during 1943-44 by explosive eruptions through Paleozoic to pre-Cambrian metamorphic rocks. The active vents, seen here on 14 February 1944, were formed in an area without previous volcanic activity. Intermittent minor explosions began on 18 September 1943. Larger explosions occurred on 27 December 1943, 13 February, and 23 July 1944. After the final eruption on 31 August, the volcano was capped by a 500-m-wide crater that now contains a small lake.
Photo courtesy of Jim Luhr (Smithsonian Institution, published in Baker, 1946).
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.