M4.2 Earthquake 28 km NE of Machalí, Chile — July 31, 2025
2025-07-31 21:34:30 UTC (2025-07-31) · approx. 4:34 PM UTC-5 local
Felt by 12 people across nearby locations.
On July 31, 2025 at 21:34 UTC, a magnitude 4.2 shallow crustal earthquake struck 28 km NE of Machalí, Chile, at a depth of 8.1 km and coordinates -34.0280°, -70.3976°. This earthquake was detected by 73 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 279, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 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
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 12 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Earthquake Details
-70.3976°E
Technical Information
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Common Questions
How strong was the magnitude 4.2 earthquake near Machalí, Chile?
The magnitude 4.2 earthquake that struck 28 km NE of Machalí, Chile on July 31, 2025 at 21:34 UTC had a depth of 8.1 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at -34.0280°, -70.3976°, which is 28 km NE of Machalí, Chile. View all earthquakes in Chile.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.2 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 4.2 event is significantly smaller than that historical record.
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Location
Authoritative source: USGS event page (event ID: us6000qx3m). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, July 31, 2025). M4.2 Earthquake 28 km NE of Machalí, Chile — July 31, 2025. Retrieved October 17, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000qx3m/