4.3

M4.3 Earthquake 73 km WNW of San Antonio de los Cobres, ArgentinaOctober 31, 2023

2023-10-31 20:29:41 UTC (2023-10-31) · approx. 4:29 PM UTC-4 local

MagnitudeM4.3(mb)
Time20:29 UTC4:29 PM UTC-4
Depth215.6 kmintermediate depth
Coordinates-24.062°, -67.026°
Felt byNo felt reports
Status✓ Reviewed by USGS

On October 31, 2023 at 20:29 UTC, a magnitude 4.3 intermediate depth earthquake struck 73 km WNW of San Antonio de los Cobres, Argentina, at a depth of 215.6 km and coordinates -24.0624°, -67.0259°.

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.

Map showing earthquake epicenter at -24.06°, -67.03°

Earthquake Details

Magnitude
4.3 mb
Depth
215.6 km
intermediate depth
Location
-24.0624°N
-67.0259°E

Technical Information

Event ID
us7000l7x0
Event Type
earthquake
Status
✓ Reviewed
Significance
284
Stations Used
25
Azimuthal Gap
69.0°
Min Station Distance
1.530°
RMS Residual
0.98 sec
Last Updated
2024-01-18 21:11:02 UTC

Common Questions

How strong was the magnitude 4.3 earthquake near San Antonio de los Cobres, Argentina?

The magnitude 4.3 earthquake that struck 73 km WNW of San Antonio de los Cobres, Argentina on October 31, 2023 at 20:29 UTC had a depth of 215.6 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.

Understanding This Data

Magnitude 4.3 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000l7x0). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, October 31, 2023). M4.3 Earthquake 73 km WNW of San Antonio de los Cobres, ArgentinaOctober 31, 2023. Retrieved January 18, 2024 from https://www.earthquaketracker.org/earthquakes/event/us7000l7x0/