M4.5 Earthquake near Antofagasta, Chile — July 31, 2023
2023-07-31 20:55:29 UTC (2023-07-31) · approx. 3:55 PM UTC-5 local
On July 31, 2023 at 20:55 UTC, a magnitude 4.5 intermediate depth earthquake struck near Antofagasta, Chile, at a depth of 115.0 km and coordinates -22.1793°, -68.7171°. This earthquake was detected by 41 seismic stations with good location accuracy and was assigned a USGS significance rating of 312, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.5 releases seismic energy equivalent to roughly 85 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 767 m — a useful intuition for the size of the slip patch on the fault.
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
Earthquake Details
-68.7171°E
Technical Information
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Common Questions
How strong was the magnitude 4.5 earthquake near Antofagasta, Chile?
The magnitude 4.5 earthquake that struck near Antofagasta, Chile on July 31, 2023 at 20:55 UTC had a depth of 115.0 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at -22.1793°, -68.7171°, which is near Antofagasta, Chile. View all earthquakes in Chile.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.5 earthquakes can continue for several days and gradually diminish over time.
Has Chile had earthquakes this big before?
The largest recorded earthquake in Chile was the M9.5 Great Chilean earthquake of May 22, 1960. Today's magnitude 4.5 event is significantly smaller than that historical record.
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Location
Authoritative source: USGS event page (event ID: us6000kwxb). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, July 31, 2023). M4.5 Earthquake near Antofagasta, Chile — July 31, 2023. Retrieved October 7, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000kwxb/