M4.2 Earthquake 44 km WSW of Arauco, Argentina — October 21, 2023
2023-10-21 20:01:07 UTC (2023-10-21) · approx. 4:01 PM UTC-4 local
On October 21, 2023 at 20:01 UTC, a magnitude 4.2 intermediate depth earthquake struck 44 km WSW of Arauco, Argentina, at a depth of 135.3 km and coordinates -28.7412°, -67.2082°.
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.
Earthquake Details
-67.2082°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.2 earthquake near Arauco, Argentina?
The magnitude 4.2 earthquake that struck 44 km WSW of Arauco, Argentina on October 21, 2023 at 20:01 UTC had a depth of 135.3 km. For context, this was a light earthquake commonly felt near the epicenter.
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.
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Understanding This Data
Magnitude 4.2 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us6000lh77). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, October 21, 2023). M4.2 Earthquake 44 km WSW of Arauco, Argentina — October 21, 2023. Retrieved December 26, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000lh77/