The Volcano That Killed 2,000 People Is Stirring Again

For the first time in more than 40 years, scientists have put this volcano back on their watch list. Its last eruption in 1982 killed nearly 2,000 people in one of Mexico's deadliest natural disasters.

The El Chichón volcano in southern Mexico is showing signs of life again. The activity doesn't suggest an imminent eruption, but it's enough to put scientists on alert. This remote, heavily forested peak has a deadly history, and scientists learned the hard way what happens when warning signs go unnoticed.

Between June and December 2025, researchers from the National Autonomous University of Mexico (UNAM) documented consistent changes inside the volcano's crater: rising temperatures, visible gas bubbling, unusual sulfur formations floating on the surface of the acidic crater lake, and chemical shifts in the water that point to active hydrothermal processes brewing beneath the surface.

For a volcano that went silent after its devastating 1982 eruption, these changes are significant. They don't necessarily mean El Chichón is preparing to erupt again, but they do mean the system is awake and evolving in ways that demand attention.

Unusual Activity Detected in the Crater Lake