Overview
- The Servicio Sismológico Nacional logged a cluster of low‑magnitude quakes between July 4 and July 6 concentrated in Oaxaca’s Istmo de Tehuantepec near Unión Hidalgo, Salina Cruz and Matías Romero.
- Recorded magnitudes ranged about M3.5–3.7 with depths varying from roughly 3 km to more than 130 km, a spread that explains why some shocks were felt more strongly than others.
- Protección Civil carried out local inspections after a shallow M3.6 near Tepeapulco, Hidalgo, and officials reported no significant damage or injuries following their checks.
- The most recent notable event was a M3.7 on July 6 located northeast of Unión Hidalgo at about 104 km depth, which SSN posted without an initial damage report.
- The activity reflects normal tectonic release where the Cocos plate subducts beneath North America, SSN/UNAM continue 24‑hour monitoring, and authorities stress preparedness rather than treating the sequence as a predictor of larger quakes.