About Aliso
Aliso is a stratovolcano rising to 4,267 meters (14,000 feet) in Ecuador's South America Volcanic Regions. The volcano is currently active, with its most recent eruption in 2450 BCE. The volcano has produced 1 recorded eruption.
Geography & Climate
Aliso is located in Ecuador, within the Northern Andean Volcanic Arc of the broader South America Volcanic Regions. Situated at 0.53° S, 78.00° W in the Southern Hemisphere, the volcano lies within a tropical climate zone. Standing at 4,267 meters above sea level, Aliso towers above the alpine zone, where vegetation gives way to bare rock, snow, and ice for much of the year. The high elevation means the upper slopes experience significantly colder temperatures than surrounding lowlands. The volcanic landform is characterized as a composite, which describes the physical shape and structure of the volcanic edifice as observed from the surface.
Geological Context
Aliso sits in a subduction zone, where one tectonic plate dives beneath another, creating intense heat and pressure that generates magma. Subduction zones are responsible for many of the world's most explosive volcanoes and deadliest eruptions. For communities in Ecuador near Aliso, this tectonic setting means the volcano is capable of producing powerful explosive eruptions, pyroclastic flows, and lahars that can threaten populated areas within tens of kilometers of the summit. The dominant rock type is andesite / basaltic andesite, a dark, fine-grained volcanic rock that forms from rapidly cooling, low-viscosity lava. Basaltic eruptions tend to be less explosive and produce fluid lava flows that can travel long distances. While less immediately dangerous than explosive eruptions, basaltic lava flows can destroy structures and infrastructure in their path, and volcanic gases released during these eruptions can affect air quality over a wide area.
Eruption History Summary
Aliso has 1 recorded eruption in the geological database, spanning from 2450 BCE to 2450 BCE.
GVP Reference Summary
The Aliso volcanic complex lies at the eastern foot of the Ecuadorian Andes, east of Antisana volcano and SW of the town of Baeza. The largely unexplored complex contains an arcuate summit ridge on the west with older andesitic lava flows and tundra-like vegetation, and rhyolitic and dacitic lava domes in a wet cloud-forest environment on the lower eastern flanks. The Pumayacu center on the SE flank contains several lava domes along a NNE axis parallel to the Andean Thrust Fault System (TFZ). Morphologically young andesitic lava flows occur along the flat-topped ridge above Baeza town. The Pumayacu center erupted pyroclastic-flow deposits of late Pleistocene and Holocene age. One pyroclastic-flow deposit was dated at about 4,400 BP, and a pumice lapilli layer overlies a ceramic-rich cultural horizon thought to be about 2,000 years old.
— Smithsonian Institution, Global Volcanism Program
1 Recorded Eruption
| Year | VEI | Type | Area |
|---|---|---|---|
| 2450 BCE | — | Confirmed Eruption | Pumayucu |
Real-Time Data
USGS Alert Level
Thermal Anomalies
Frequently Asked Questions About Aliso
Is Aliso an active volcano?+
Aliso is not currently classified as active. Its activity evidence is listed as "Eruption Dated." The last known eruption was in 2450 BCE. However, no volcano is ever considered permanently extinct.
When did Aliso last erupt?+
The most recent recorded eruption of Aliso occurred in 2450 BCE. The eruption was classified as a "Confirmed Eruption." Aliso has 1 recorded eruption in total.
How high is Aliso?+
Aliso has a summit elevation of 4,267 meters (14,000 feet) above sea level. At 4,267 meters, it stands taller than Mount Rainier (4,392m) and is among the world's major volcanic peaks.
What type of volcano is Aliso?+
Aliso is classified as a Stratovolcano. Stratovolcanoes (also called composite volcanoes) are steep, conical volcanoes built up by many layers of hardened lava, tephra, and volcanic ash. They are among the most common and dangerous types, known for explosive eruptions.
Where is Aliso located?+
Aliso is located in Ecuador, in the South America Volcanic Regions. More specifically, it lies within the Northern Andean Volcanic Arc. Its exact coordinates are -0.530° latitude, -78.000° longitude.
Is it safe to visit Aliso?+
Aliso can generally be visited, but as with any volcano, visitors should check local conditions and any advisory notices before traveling. Ecuador may have specific regulations for accessing volcanic areas. Guided tours are often the safest and most informative way to experience a volcano.
