4.3

M4.3 Earthquake 32 km W of San Antonio, Chile — June 6, 2021

2021-06-06 19:42:34 UTC (2021-06-06) · approx. 2:42 PM UTC-5 local

MagnitudeM4.3(mb)
Time19:42 UTC≈ 2:42 PM UTC-5
Depth30.5 kmshallow crustal
Coordinates-33.600°, -71.953°
Felt byNo felt reports
Status✓ Reviewed by USGS

On June 6, 2021 at 19:42 UTC, a magnitude 4.3 shallow crustal earthquake struck 32 km W of San Antonio, Chile, at a depth of 30.5 km and coordinates -33.6000°, -71.9525°.

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 5.2 mainshock that occurred 2 days ago 62 km SW of San Antonio, Chile. 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 -33.60°, -71.95°

Earthquake Details

Magnitude
4.3 mb
Depth
30.5 km
shallow crustal
Location
-33.6000°N
-71.9525°E

Technical Information

Event ID
us7000eaj0
Event Type
earthquake
Status
✓ Reviewed
Significance
284
Azimuthal Gap
166.0°
Min Station Distance
0.287°
RMS Residual
0.77 sec
Last Updated
2021-08-24 21:34:45 UTC

Common Questions

How strong was the magnitude 4.3 earthquake near San Antonio, Chile?

The magnitude 4.3 earthquake that struck 32 km W of San Antonio, Chile on June 6, 2021 at 19:42 UTC had a depth of 30.5 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 M5.2 one earlier?

No. This magnitude 4.3 earthquake is an aftershock of the larger magnitude 5.2 mainshock that occurred earlier 62 km SW of San Antonio, Chile. 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: us7000eaj0). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, June 6, 2021). M4.3 Earthquake 32 km W of San Antonio, Chile — June 6, 2021. Retrieved August 24, 2021 from https://www.earthquaketracker.org/earthquakes/event/us7000eaj0/