Overview
- The earthquake of July 17 near Ciudad Hidalgo, Chiapas, generated a long aftershock series that the Servicio Sismológico Nacional logged at 593 replicas through July 20 and identified a largest secondary of magnitude 6.5.
- Multiple moderate tremors continued along the Chiapas coast between July 18 and July 21, with recent quakes ranging about magnitude 3.9 to 4.8 and depths near 10–16 km, keeping monitoring teams on alert.
- Authorities report no major damage or casualties from the most recent Mexican events so far but are carrying out inspections and recommending that residents check for cracks in walls, columns, and foundations.
- In Peru, the IGP recorded a magnitude-3.5 quake near Chupaca on July 21 while Arequipa officials warned that only about 20% of homes meet technical building standards and roughly 60% of houses in some districts are precarious.
- Scientists stress that exact timing of large quakes cannot be predicted so emergency agencies are urging practical readiness: secure heavy objects, keep a mochila de emergencia, know evacuation routes and run drills.