4.2

M4.2 Earthquake 69 km SW of San Antonio, ChileApril 28, 2026

2026-04-28 10:04:20 UTC (4 hours ago) · approx. 5:04 AM UTC-5 local

MagnitudeM4.2(mwr)
Time10:04 UTC5:04 AM UTC-5
Depth24.3 kmshallow crustal
Coordinates-33.961°, -72.218°
Felt byNo felt reports
Status✓ Reviewed by USGS

On April 28, 2026 at 10:04 UTC, a magnitude 4.2 shallow crustal earthquake struck 69 km SW of San Antonio, Chile, at a depth of 24.3 km and coordinates -33.9607°, -72.2184°.

Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at -33.96°, -72.22°

Earthquake Details

Magnitude
4.2 mwr
Depth
24.3 km
shallow crustal
Location
-33.9607°N
-72.2184°E

Technical Information

Event ID
us7000sgmn
Event Type
earthquake
Status
✓ Reviewed
Significance
271
Stations Used
44
Azimuthal Gap
143.0°
Min Station Distance
0.587°
RMS Residual
0.94 sec
Last Updated
2026-04-28 13:23:13 UTC

Common Questions

How strong was the magnitude 4.2 earthquake near San Antonio, Chile?

The magnitude 4.2 earthquake that struck 69 km SW of San Antonio, Chile on April 28, 2026 at 10:04 UTC had a depth of 24.3 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 4.2 earthquakes can continue for several days and gradually diminish over time.

What should I do after an earthquake?

If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.

Authoritative source: USGS event page (event ID: us7000sgmn). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, April 28, 2026). M4.2 Earthquake 69 km SW of San Antonio, ChileApril 28, 2026. Retrieved April 28, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000sgmn/