M4.3 Earthquake 59 km W of San Antonio de los Cobres, Argentina — October 17, 2023
2023-10-17 21:45:30 UTC (2023-10-17) · approx. 5:45 PM UTC-4 local
On October 17, 2023 at 21:45 UTC, a magnitude 4.3 intermediate depth earthquake struck 59 km W of San Antonio de los Cobres, Argentina, at a depth of 186.7 km and coordinates -24.2210°, -66.9054°.
Physical scale: An earthquake of magnitude 4.3 releases seismic energy equivalent to roughly 43 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 558 m — a useful intuition for the size of the slip patch on the fault.
This earthquake is part of an ongoing aftershock sequence following the magnitude 5.3 mainshock that occurred 29 days ago 43 km NW of San Antonio de los Cobres, Argentina. Since the mainshock, the USGS has recorded 1 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
Earthquake Details
-66.9054°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.3 earthquake near San Antonio de los Cobres, Argentina?
The magnitude 4.3 earthquake that struck 59 km W of San Antonio de los Cobres, Argentina on October 17, 2023 at 21:45 UTC had a depth of 186.7 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 4.3 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.3 one earlier?
No. This magnitude 4.3 earthquake is an aftershock of the larger magnitude 5.3 mainshock that occurred earlier 43 km NW of San Antonio de los Cobres, Argentina. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
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Understanding This Data
Magnitude 4.3 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us6000lg8c). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, October 17, 2023). M4.3 Earthquake 59 km W of San Antonio de los Cobres, Argentina — October 17, 2023. Retrieved December 26, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000lg8c/