Scientists from the National Autonomous University of Mexico (UNAM) documented a number of changes inside Mexico's El Chichón volcano during monitoring between June and December 2025. El Chichón's last eruption in 1982 was one of Mexico's deadliest volcanic disasters, killing at least 1,900 people. So any renewed activity at the volcano—even minor, often "harmless" changes—demands close monitoring given its catastrophic history. Researchers from UNAM documented several key changes. The crater