Overview
- The National Seismological Service reported a magnitude 4.2 earthquake at 2:59 a.m. on December 28 south of Las Choapas, Veracruz, at a depth of 160.7 km.
- Mexico City's seismic alert did not sound because the event did not meet activation criteria evaluated by the Mexican Seismic Alert System.
- A magnitude 3.6 quake was recorded at 4:38 p.m. on December 27 southwest of Tuxtepec, Oaxaca, at a depth of 5 km.
- City civil protection guidance indicates alerts generally trigger for quakes near magnitude 6 when distance allows measurable lead time.
- Authorities noted that microquakes under magnitude 4 typically cannot be warned in time, and they reiterated standard safety steps such as staying calm, moving to designated safety zones, and avoiding elevators and glass.