4.0

M4.0 Earthquake 69 km WNW of La Ligua, ChileSeptember 14, 2025

2025-09-14 14:32:25 UTC (2025-09-14) · approx. 9:32 AM UTC-5 local

MagnitudeM4.0(mb)
Time14:32 UTC9:32 AM UTC-5
Depth32.3 kmshallow crustal
Coordinates-32.146°, -71.879°
Felt byNo felt reports
Status✓ Reviewed by USGS

On September 14, 2025 at 14:32 UTC, a magnitude 4.0 shallow crustal earthquake struck 69 km WNW of La Ligua, Chile, at a depth of 32.3 km and coordinates -32.1463°, -71.8790°.

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 5.1 mainshock that occurred 14 days ago 54 km NNW of Valparaíso, Chile. Since the mainshock, the USGS has recorded 3 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 -32.15°, -71.88°

Earthquake Details

Magnitude
4.0 mb
Depth
32.3 km
shallow crustal
Location
-32.1463°N
-71.8790°E

Technical Information

Event ID
us7000qw61
Event Type
earthquake
Status
✓ Reviewed
Significance
246
Stations Used
27
Azimuthal Gap
141.0°
Min Station Distance
0.774°
RMS Residual
0.68 sec
Last Updated
2025-12-03 03:58:32 UTC

Common Questions

How strong was the magnitude 4.0 earthquake near La Ligua, Chile?

The magnitude 4.0 earthquake that struck 69 km WNW of La Ligua, Chile on September 14, 2025 at 14:32 UTC had a depth of 32.3 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 4.0 earthquakes can continue for several days and gradually diminish over time.

Is this the same earthquake as the M5.1 one earlier?

No. This magnitude 4.0 earthquake is an aftershock of the larger magnitude 5.1 mainshock that occurred earlier 54 km NNW of Valparaíso, 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: us7000qw61). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, September 14, 2025). M4.0 Earthquake 69 km WNW of La Ligua, ChileSeptember 14, 2025. Retrieved December 3, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000qw61/