Atacazo
Stratovolcano in Ecuador
Key Facts
Elevation
4,463 m (14,642 ft)
Type
Stratovolcano
Location
-0.353°, -78.617°
Region
Northern Andean Volcanic Arc
Rock Type
Andesite / Basaltic Andesite
Tectonic Setting
Subduction zone
Location
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Overview
Atacazo, located about 25 km SW of Quito, consists of a large Pleistocene andesitic stratovolcanoes truncated by a late-Pleistocene to Holocene caldera. Growth of the La Carcacha edifice was followed by construction of Atacazo, a stratovolcano with flank lava domes. The 6-km-wide caldera, which is breached to the SW, is partially filled by three dacitic Holocene lava-dome complexes.
Two andesitic lava domes are also found on the SE flank. Several plinian eruptions have occurred at the Atacazo-Ninahuilca complex during the Holocene, accompanied by growth of lava domes. The latest dated eruption took place about 2300 years ago, forming the Ninahuilca Chico lava domes within the summit caldera.
Dome formation was accompanied by Plinian explosive eruptions and pyroclastic flows that traveled 35 km down valleys to the west.
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 | 2346 years ago | Historical | Historically active |
Monitoring & Alert Status
Monitoring Networks
Current Status
Nearby Volcanoes in South America Volcanic Regions
Quick Info
- •Smithsonian ID: 352021
- •Evidence: Eruption Dated
- •Epoch: Holocene
About the Photo
Atacazo stratovolcano, located 20 km south of Quito, is seen here from the west along the road to Guayaquil. The volcano contains a summit caldera that is partially filled by lava domes of Holocene age. Lava domes are also found on the SE flank. The only dated Holocene eruption took place about 2400 years ago, forming the Ninahuilca lava domes, the peaks below the center horizon.
Photo by John Ewert, 1992 (U.S. Geological Survey).
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.