M3.9 Earthquake 83 km W of Illapel, Chile — October 16, 2021
2021-10-16 20:14:46 UTC (2021-10-16) · approx. 3:14 PM UTC-5 local
On October 16, 2021 at 20:14 UTC, a magnitude 3.9 shallow crustal earthquake struck 83 km W of Illapel, Chile, at a depth of 16.0 km and coordinates -31.6739°, -72.0526°.
Physical scale: An earthquake of magnitude 3.9 releases seismic energy equivalent to roughly 11 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 296 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
-72.0526°E
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Common Questions
How strong was the magnitude 3.9 earthquake near Illapel, Chile?
The magnitude 3.9 earthquake that struck 83 km W of Illapel, Chile on October 16, 2021 at 20:14 UTC had a depth of 16.0 km. For context, this was a minor earthquake typically detected only by instruments.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.9 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 3.9 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us6000fv9z). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, October 16, 2021). M3.9 Earthquake 83 km W of Illapel, Chile — October 16, 2021. Retrieved December 25, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000fv9z/