Sumaco

Stratovolcano in Ecuador

Last Eruption: 1895

Key Facts

Elevation

3,990 m (13,091 ft)

Type

Stratovolcano

Location

-0.538°, -77.626°

Region

Northern Andean Volcanic Arc

Rock Type

Trachybasalt / Tephrite Basanite

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

The forested Sumaco stratovolcano rises above the jungles of the western Amazon basin, east of Antisana volcano, and occupies an isolated position far to the east of the main Andes volcanic axis. Constructed over Cretaceous sedimentary rocks, it forms a relatively symmetrical cone in an area of heavy rainfall and erosion. Sumaco has produced alkaline tephritic, basanitic, and phonolitic rocks distinct from those of the main Andean chain.

The volcano has a broad summit crater, 300 x 400 m wide, containing a central cone. Reports of historical eruptions are somewhat ambiguous; an eruption is inferred in the 18th or early-19th century on the basis of changes in crater morphology.

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

Trachybasalt / Tephrite Basanite

Silica Content

Varied composition

Tectonic Setting

Subduction zone

Formed by oceanic plate subduction, typically producing explosive eruptions due to water-rich magmas.

Age & Formation

Epoch

Holocene

Evidence

Evidence Uncertain

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	131 years ago	Historical	Historically active

Monitoring & Alert Status

Monitoring Networks

Global Volcanism Program

International eruption database

Current Status

Normal

No recent activity. Routine monitoring continues.

Nearby Volcanoes in South America Volcanic Regions

Regional Volcanic Activity

The South America 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: 352040
•Evidence: Evidence Uncertain
•Epoch: Holocene

About the Photo

Forested Sumaco volcano rises to 3990 m above the jungles of the western Amazon basin and is seen here in an unusually cloud-free view NE of the road from Baeza to Tena. Sumaco is part of a north-south-trending volcanic chain far to the east of the main Andes volcanic axis and has erupted more alkaline rocks distinct from those of the main chain. Reports of historical eruptions are somewhat ambiguous, although the volcano maintains its symmetrical shape despite heavy rainfall and intense erosion.

Photo by Ursy Potter, 2005.