Overview
- Argentina’s INPRES recorded a shallow magnitude 4.3 quake that was felt in Salta, Catamarca and Tucumán and had a reported hypocenter about 5 kilometers deep.
- Mexico’s Servicio Sismológico Nacional logged a magnitude 3.5 near Matías Romero at about 103 kilometers depth and a magnitude 3.7 near Santa Rosalía at about 10 kilometers depth.
- The SSN published a consolidated morning report updated to 05:00 on October 8 that lists multiple events under magnitude 4.0 detected during the night and early morning.
- Authorities and local protection civil units reported no material damage or casualties and said daily life and services continued to operate normally in the affected areas.
- Seismologists note that shallow quakes transmit stronger shaking at the surface while deeper events are less felt, and agencies use these low‑magnitude records to improve hazard analysis and public preparedness.