Renewed Activity Detected at Mexico's El Chichón Volcano After Decades of Dormancy

The El Chichón volcano in Mexico is garnering renewed scientific interest after unusual activity indicators were detected following more than four decades of dormancy. This development has prompted research teams in Mexico to enhance monitoring efforts, amid concerns that these indicators could lead to more hazardous volcanic activity in the future.

Temperature Increases and Unusual Gas Emissions

Researchers from the National Autonomous University of Mexico reported that monitoring operations conducted between June and December 2025 revealed a significant rise in temperatures within the volcano's crater, along with atypical gas emissions and the formation of new sulfur deposits. This volcano is among the most dangerous in the country’s history, having claimed approximately 2,000 lives during its eruption in 1982 and causing widespread damage.

Color Change in Crater Lake as a Geological Indicator

Scientists have observed a striking change in the color of the crater lake, shifting from green to gray, indicating an increase in sulfate and silica concentrations in the water. Thermal measurements also showed a clear rise in temperatures at the lake's bottom and surrounding areas, reflecting internal activity within the volcano's structure.

Toxic Gases Raise Environmental Concerns

Researchers have detected emissions of hydrogen sulfide and carbon dioxide, gases that can pose health risks if they accumulate in low-lying or enclosed areas. Scientists emphasize that these emissions require close monitoring to assess their impact on local populations and the surrounding environment.

Hydrothermal Activity Not Signaling Imminent Eruption

Despite the recorded indicators, experts clarified that the current activity is likely due to hydrothermal reactions, resulting from heated groundwater interacting with rocks, rather than magma movement beneath the surface. Volcanologist Patricia Giacomi Paz confirmed that the observed behavior corresponds to limited steam explosions, while seismic data indicate relatively low levels of activity.

Comparison to the 1982 Eruption and Future Warnings

Scientists noted that current data do not resemble the conditions preceding the devastating eruption of the 1980s, but they cautioned that volcanoes can remain active for decades or even centuries after major eruptions. Researchers believe that monitoring subtle changes in temperature, water composition, and gas emissions could provide early indicators of any potential internal transformations.

Modern Technologies to Enhance Monitoring and Public Safety

The research team is employing a range of advanced technologies to monitor the volcano, including satellite remote sensing, drones, and ground-based devices to measure gas emissions and land deformation. Scientists assert that ongoing monitoring is crucial to mitigate potential risks and ensure the safety of communities near the volcano.