M3.4 Earthquake 87 km NW of San Antonio, Puerto Rico — April 28, 2026
2026-04-28 07:49:07 UTC (3 hours ago) · approx. 2:49 AM UTC-5 local
On April 28, 2026 at 07:49 UTC, a magnitude 3.4 shallow crustal earthquake struck 87 km NW of San Antonio, Puerto Rico, at a depth of 5.1 km and coordinates 19.0488°, -67.6887°.
Physical scale: An earthquake of magnitude 3.4 releases seismic energy equivalent to roughly 2.0 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 136 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
-67.6887°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.4 earthquake near San Antonio, Puerto Rico?
The magnitude 3.4 earthquake that struck 87 km NW of San Antonio, Puerto Rico on April 28, 2026 at 07:49 UTC had a depth of 5.1 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.
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Understanding This Data
Magnitude 3.4 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: pr71514928). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, April 28, 2026). M3.4 Earthquake 87 km NW of San Antonio, Puerto Rico — April 28, 2026. Retrieved April 28, 2026 from https://www.earthquaketracker.org/earthquakes/event/pr71514928/