M4.6 Earthquake 55 km W of San Alejandro, Peru — September 22, 2025
2025-09-22 20:48:23 UTC (2025-09-22) · approx. 3:48 PM UTC-5 local
On September 22, 2025 at 20:48 UTC, a magnitude 4.6 intermediate depth earthquake struck 55 km W of San Alejandro, Peru, at a depth of 122.6 km and coordinates -8.8757°, -75.7111°. This earthquake was detected by 52 seismic stations with good location accuracy and was assigned a USGS significance rating of 326, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.6 releases seismic energy equivalent to roughly 120 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 899 m — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in Peru, a region characterized by the northern Peru-Chile subduction zone, complicated by the subduction of the Nazca Ridge. The nearest mapped fault system is the Peru-Chile Trench. View all earthquakes in Peru.
Learn more: Magnitude scale · Aftershock sequences
Earthquake Details
-75.7111°E
Technical Information
Common Questions
How strong was the magnitude 4.6 earthquake near San Alejandro, Peru?
The magnitude 4.6 earthquake that struck 55 km W of San Alejandro, Peru on September 22, 2025 at 20:48 UTC had a depth of 122.6 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at -8.8757°, -75.7111°, which is 55 km W of San Alejandro, Peru. View all earthquakes in Peru.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.6 earthquakes can continue for several days and gradually diminish over time.
Has Peru had earthquakes this big before?
The largest recorded earthquake in Peru was the M8.0 Arequipa earthquake of June 23, 2001. Today's magnitude 4.6 event is significantly smaller than that historical record.
What should I do after an earthquake?
If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.
Authoritative source: USGS event page (event ID: us6000rc64). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, September 22, 2025). M4.6 Earthquake 55 km W of San Alejandro, Peru — September 22, 2025. Retrieved May 28, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000rc64/