Overview
- The Servicio Sismológico Nacional recorded a cluster of low-magnitude earthquakes on July 2–3 across Oaxaca and parts of Chiapas, with magnitudes mostly between about 3.5 and 3.9.
- Notable events reported by the SSN included shallow quakes near Salina Cruz (about 3.8–3.9 at ~10–18 km depth) and Tonalá, Chiapas (3.6 at ~4 km) plus deeper events near Matías Romero and Unión Hidalgo (around 3.6–3.7 at depths near 100–122 km) and a 3.6 near Juchitán de Zaragoza at 66 km.
- Authorities say there are no reports of significant structural damage or casualties and Protección Civil and the SSN are maintaining round‑the‑clock monitoring of the area.
- Depth differences matter because very shallow events can boost local shaking near the epicenter while deeper intermediate events tend to lose energy before reaching the surface but can be felt across a wider area.
- The activity is consistent with routine seismicity along the Cocos‑plate subduction margin that the SSN and UNAM continuously monitor, and officials are urging residents to review emergency plans and check gas and electrical installations as a precaution.