🌋VolcanoAtlas

El Chichón

Mexico's Deadliest Modern Eruption

Elevation

1,150 m

Last Eruption

1982

Type

Lava dome(s)

Country

Mexico

Location

Loading map...

Volcanic Hazards & Risk Assessment

Primary Hazards

  • Lava flows and fountaining
  • Volcanic gas emissions
  • Local explosive activity

Risk Level

Population at RiskModerate
Infrastructure RiskHigh
Aviation RiskSignificant

Geological Composition & Structure

Rock Types

Primary
Unknown
Silica Content
Varied composition

Tectonic Setting

Unknown
Intraplate setting with hotspot or regional volcanic activity.

Age & Formation

Epoch
Unknown
Evidence
Unknown

Eruption Statistics & Analysis

MetricValueGlobal RankingSignificance
Total Recorded EruptionsUnknownLowModerately active volcano
Maximum VEIVEI UnknownMinorLocal impact potential
Recent Activity44 years agoRecentRecently active

Monitoring & Alert Status

Monitoring Networks

Global Volcanism Program
International eruption database

Current Status

Watch
Dormant but monitored. Capable of renewed activity.

Authority Sources

Smithsonian GVP
Official volcano database

Related Volcanoes

All Mexico Volcanoes
Explore by country
Lava dome(s) Volcanoes
By volcano type
Chiapas
Regional volcanoes

Other Volcanoes in Mexico

Interesting Facts

🌋

El Chichón's 1982 eruption injected 7–10 megatons of SO₂ into the stratosphere — more than any eruption since Krakatau in 1883 — despite being a relatively modest VEI 5 event.

🌋

The 1982 eruption killed approximately 2,000 people, making it the deadliest volcanic event in Mexican history in the modern era.

🌋

Global temperatures decreased by approximately 0.3–0.5°C in the 1–2 years following the eruption due to stratospheric sulfuric acid aerosols.

🌋

Before 1982, El Chichón was so poorly known that it did not appear on most Mexican volcanic hazard maps despite being capable of VEI 5 eruptions.

🌋

The eruption destroyed nine Zoque indigenous villages and virtually the entire population of Francisco León, a village of approximately 1,000 people at the volcano's base.

🌋

Four VEI 5 eruptions in the past ~4,000 years give El Chichón one of the highest ratios of large eruptions to total eruptions of any volcano on Earth.

🌋

The crater lake formed after 1982 has a pH as low as 1.7 — roughly as acidic as stomach acid — and temperatures reaching 52°C.

🌋

El Chichón's magma contains abundant anhydrite (calcium sulfate), a mineral rarely found in volcanic rocks, which explains its exceptional sulfur output.

🌋

The 1982 eruption's global cooling effect demonstrated that volcanic sulfur content, not just eruption volume, determines a volcano's climate impact.

🌋

The Chiapanecan Volcanic Arc, where El Chichón sits, is separated from Mexico's main Transmexican Volcanic Belt by over 300 km.

🌋

The 1982 disaster contributed directly to the establishment of Mexico's Centro Nacional de Prevención de Desastres (CENAPRED) in 1988.

🌋

The ~780 CE eruption of El Chichón has been proposed as a potential factor in disruptions to Classic Maya civilization, though the link remains debated.

Frequently Asked Questions

When did El Chichón erupt?
El Chichón's most recent and most devastating eruption occurred from March 28 to April 4, 1982, in three major explosive phases. The eruption destroyed the summit lava dome, killed approximately 2,000 people, and injected massive quantities of sulfur dioxide into the stratosphere, causing measurable global cooling. The volcano has produced 13 known eruptions since ~6510 BCE, with four reaching VEI 5. The recurrence interval for major eruptions is approximately 600–1,200 years.
How many people died in the 1982 El Chichón eruption?
Approximately 2,000 people died in the 1982 eruption, making it the deadliest volcanic event in modern Mexican history. Most fatalities occurred in nine Zoque indigenous villages within 8 km of the volcano, destroyed by pyroclastic flows and surges on April 3–4. The village of Francisco León lost virtually all ~1,000 residents who had not evacuated. Precise figures are uncertain because of the remote, indigenous character of the affected communities and limited pre-eruption census data.
Is El Chichón still active?
Yes, El Chichón is classified as an active volcano. Although it has not erupted since 1982, the crater formed by that eruption hosts an acidic lake (pH as low as 1.7, temperature up to 52°C) and active fumaroles emitting sulfurous gases at temperatures exceeding 100°C. These features confirm ongoing magmatic and hydrothermal activity beneath the volcano. Periodic seismic swarms and gas flux increases are detected by monitoring instruments. With four VEI 5 eruptions in 4,000 years, future eruptions are considered likely.
How did El Chichón affect global climate?
El Chichón's 1982 eruption injected 7–10 megatons of sulfur dioxide into the stratosphere — an enormous quantity for a VEI 5 eruption, comparable to the much larger 1991 Pinatubo eruption. The SO₂ converted to sulfuric acid aerosols that encircled the globe within three weeks, reflecting sunlight and reducing global average temperatures by approximately 0.3–0.5°C for 1–2 years. The eruption established the scientific principle that volcanic sulfur content, not erupted volume alone, determines climate impact.
What type of volcano is El Chichón?
El Chichón is a lava dome complex — a type of volcano built by the extrusion of viscous, gas-rich magma that piles up around the vent rather than flowing far downhill. Lava dome volcanoes are typically small but can produce devastatingly explosive eruptions when pressurized gas escapes catastrophically. El Chichón's trachyandesitic magma is unusually rich in sulfur (containing anhydrite), which made the 1982 eruption disproportionately impactful on global climate despite the volcano's modest size.
Where is El Chichón located?
El Chichón is located in the Francisco León municipality of Chiapas state in southeastern Mexico, at approximately 17.36°N, 93.23°W. It sits within the Chiapanecan Volcanic Arc, a chain of volcanic centers geographically isolated from Mexico's main Transmexican Volcanic Belt by over 300 km. The nearest town is Pichucalco, approximately 25 km to the north. The regional capital Villahermosa (Tabasco) is about 80 km north.
Could El Chichón erupt again?
Yes, future eruptions at El Chichón are considered likely. The volcano has produced four VEI 5 eruptions in the past ~4,000 years, with a rough recurrence interval of 600–1,200 years. The current repose period since 1982 is short by historical standards. Active fumaroles, an acidic crater lake, and periodic seismic increases confirm the magmatic system remains active. ~40,000–50,000 people now live within 15 km, and CENAPRED maintains monitoring and hazard plans.
Why was the 1982 eruption so deadly?
The 1982 eruption was devastating because El Chichón was virtually unknown as a volcanic hazard. The volcano did not appear on most hazard maps, no monitoring was in place, and no evacuation plans existed for the surrounding Zoque indigenous villages. When pyroclastic flows swept down the flanks on April 3–4 at speeds exceeding 100 km/h, communities within 8 km had received inadequate warning. The remoteness of the Chiapas highlands, limited road access, and the political marginalization of indigenous communities all compounded the disaster. The event led to major reforms in Mexico's disaster preparedness.