M4.9 Earthquake 100 km E of La Tirana, Chile — October 26, 2026

On October 26, 2026 at 19:36 UTC, a magnitude 4.9 intermediate depth earthquake struck 100 km E of La Tirana, Chile, at a depth of 119.5 km and coordinates -20.3438°, -68.6903°. This earthquake was detected by 61 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 369, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 4.9 releases seismic energy equivalent to roughly 338 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.4 km — a useful intuition for the size of the slip patch on the fault.

This earthquake is part of an ongoing aftershock sequence following the magnitude 5.1 mainshock that occurred 17 days ago 72 km SSW of Colchane, Chile. Since the mainshock, the USGS has recorded 0 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.

The epicenter is located in Chile, a region characterized by the Peru-Chile Trench, where the Nazca Plate subducts beneath South America at 65-80 mm per year. The nearest mapped fault system is the Peru-Chile Trench. View all earthquakes in Chile.

Learn more: Magnitude scale · Aftershock sequences