M3.3 Earthquake 53 km N of Brenas, Puerto Rico — October 21, 2026
2026-10-21 05:01:30 UTC (1 hour ago) · approx. 1:01 AM UTC-4 local
On October 21, 2026 at 05:01 UTC, a magnitude 3.3 shallow crustal earthquake struck 53 km N of Brenas, Puerto Rico, at a depth of 26.3 km and coordinates 18.9493°, -66.3172°.
Physical scale: An earthquake of magnitude 3.3 releases seismic energy equivalent to roughly 1.2 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 109 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
-66.3172°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.3 earthquake near Brenas, Puerto Rico?
The magnitude 3.3 earthquake that struck 53 km N of Brenas, Puerto Rico on October 21, 2026 at 05:01 UTC had a depth of 26.3 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 3.3 earthquakes can continue for several days and gradually diminish over time.
Actions
Understanding This Data
Magnitude 3.3 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: pr71537388). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, October 21, 2026). M3.3 Earthquake 53 km N of Brenas, Puerto Rico — October 21, 2026. Retrieved October 21, 2026 from https://www.earthquaketracker.org/earthquakes/event/pr71537388/