M3.6 Earthquake 39 km NNW of San Antonio, Puerto Rico — July 28, 2026
2026-07-28 23:50:06 UTC (1 hour ago) · approx. 7:50 PM UTC-4 local
On July 28, 2026 at 23:50 UTC, a magnitude 3.6 shallow crustal earthquake struck 39 km NNW of San Antonio, Puerto Rico, at a depth of 9.0 km and coordinates 18.8081°, -67.2778°.
Physical scale: An earthquake of magnitude 3.6 releases seismic energy equivalent to roughly 3.8 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 184 m — a useful intuition for the size of the slip patch on the fault.
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 1 citizen response to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Earthquake Details
-67.2778°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.6 earthquake near San Antonio, Puerto Rico?
The magnitude 3.6 earthquake that struck 39 km NNW of San Antonio, Puerto Rico on July 28, 2026 at 23:50 UTC had a depth of 9.0 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 3.6 earthquakes can continue for several days and gradually diminish over time.
Actions
Understanding This Data
Magnitude 3.6 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: pr2026209003). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, July 28, 2026). M3.6 Earthquake 39 km NNW of San Antonio, Puerto Rico — July 28, 2026. Retrieved July 29, 2026 from https://www.earthquaketracker.org/earthquakes/event/pr2026209003/