4.0

M4.0 Earthquake 83 km SW of San Antonio, Chile — July 3, 2024

2024-07-03 22:39:59 UTC (2024-07-03) · approx. 5:39 PM UTC-5 local

MagnitudeM4.0(mwr)
Time22:39 UTC≈ 5:39 PM UTC-5
Depth17.8 kmshallow crustal
Coordinates-34.139°, -72.236°
Felt byNo felt reports
Status✓ Reviewed by USGS

On July 3, 2024 at 22:39 UTC, a magnitude 4.0 shallow crustal earthquake struck 83 km SW of San Antonio, Chile, at a depth of 17.8 km and coordinates -34.1388°, -72.2364°.

Physical scale: An earthquake of magnitude 4.0 releases seismic energy equivalent to roughly 15 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 347 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 17 days ago 69 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 -34.14°, -72.24°

Earthquake Details

Magnitude
4.0 mwr
Depth
17.8 km
shallow crustal
Location
-34.1388°N
-72.2364°E

Technical Information

Event ID
us7000mwya
Event Type
earthquake
Status
✓ Reviewed
Significance
246
Stations Used
49
Azimuthal Gap
141.0°
Min Station Distance
0.706°
RMS Residual
0.84 sec
Last Updated
2024-09-12 21:52:28 UTC

Common Questions

How strong was the magnitude 4.0 earthquake near San Antonio, Chile?

The magnitude 4.0 earthquake that struck 83 km SW of San Antonio, Chile on July 3, 2024 at 22:39 UTC had a depth of 17.8 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 4.0 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 4.0 earthquake is an aftershock of the larger magnitude 5.2 mainshock that occurred earlier 69 km SW of San Antonio, Chile. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.

Understanding This Data

Magnitude 4.0 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000mwya). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2024, July 3, 2024). M4.0 Earthquake 83 km SW of San Antonio, Chile — July 3, 2024. Retrieved September 12, 2024 from https://www.earthquaketracker.org/earthquakes/event/us7000mwya/