3.4

M3.4 Earthquake 8 km NNE of Brenas, Puerto RicoApril 29, 2026

2026-04-29 07:40:02 UTC (2 hours ago) · approx. 3:40 AM UTC-4 local

MagnitudeM3.4(md)
Time07:40 UTC3:40 AM UTC-4
Depth100.5 kmintermediate depth
Coordinates18.535°, -66.299°
Felt byNo felt reports
Status✓ Reviewed by USGS

On April 29, 2026 at 07:40 UTC, a magnitude 3.4 intermediate depth earthquake struck 8 km NNE of Brenas, Puerto Rico, at a depth of 100.5 km and coordinates 18.5353°, -66.2988°.

Physical scale: An earthquake of magnitude 3.4 releases seismic energy equivalent to roughly 1.8 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 132 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 18.54°, -66.30°

Earthquake Details

Magnitude
3.4 md
Depth
100.5 km
intermediate depth
Location
18.5353°N
-66.2988°E

Technical Information

Event ID
pr71515018
Event Type
earthquake
Status
✓ Reviewed
Significance
177
Stations Used
36
Azimuthal Gap
189.0°
Min Station Distance
0.224°
RMS Residual
0.23 sec
Last Updated
2026-04-29 09:48:03 UTC

Common Questions

How strong was the magnitude 3.4 earthquake near Brenas, Puerto Rico?

The magnitude 3.4 earthquake that struck 8 km NNE of Brenas, Puerto Rico on April 29, 2026 at 07:40 UTC had a depth of 100.5 km. For context, this was a minor earthquake typically detected only by instruments.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.4 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: pr71515018). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, April 29, 2026). M3.4 Earthquake 8 km NNE of Brenas, Puerto RicoApril 29, 2026. Retrieved April 29, 2026 from https://www.earthquaketracker.org/earthquakes/event/pr71515018/