Ngozi
Caldera in Tanzania
Key Facts
Elevation
2,614 m (8,576 ft)
Type
Caldera
Location
-9.004°, 33.552°
Region
Rukwa Rift Volcanic Province
Rock Type
Trachyte / Trachydacite
Tectonic Setting
Rift zone
Location
Loading map...
Overview
Ngozi caldera is the most prominent volcanic feature of the Poroto Ridge, a transverse structure at the northern end of the Karonga basin. The trachytic-to-phonolitic volcano contains a 3-km-wide caldera with a 1. 5 x 2.
5 km lake in the southern part of the caldera that is bounded by steep-walled cliffs 150-300 m high. Numerous pyroclastic cones are situated along the ridge. Eruption of the Kitulo Pumice, radiocarbon dated at about 10,200 cal.
years before present, is though to be related to formation of the caldera. The youngest activity appears to have originated from the caldera and from youthful-looking pyroclastic cones to the north; the youngest known eruption produced a pyroclastic flow that swept at least 10 km S about 500 years ago.
Volcanic Hazards & Risk Assessment
Primary Hazards
- Pyroclastic flows and surges
- Large explosive eruptions (VEI 4+)
- Ash fall and tephra deposits
- Lahars and debris flows
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 | 576 years ago | Historical | Historically active |
Monitoring & Alert Status
Monitoring Networks
Current Status
Nearby Volcanoes in Eastern Africa Volcanic Regions
Quick Info
- •Smithsonian ID: 222164
- •Evidence: Eruption Dated
- •Epoch: Holocene
About the Photo
Lake-filled Ngozi caldera is seen here from its southern rim. The 1.5 x 2.5 km caldera lake is bounded by steep-walled cliffs 150-300 m high. The caldera is the most prominent volcanic feature of the Poroto Ridge, a transverse structure at the northern end of the Karonga basin in SW Tanzania. Numerous cones are situated along the ridge. The youngest activity along the ridge appears to have originated from Ngozi caldera and from pyroclastic cones to the N.
Photo by David Williamson, CNRS, France.
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.