3.1

M3.1 Earthquake 5 km SW of Guánica, Puerto RicoSeptember 19, 2026

2026-09-19 05:06:57 UTC (3 hours ago) · approx. 1:06 AM UTC-4 local

MagnitudeM3.1(md)
Time05:06 UTC1:06 AM UTC-4
Depth7.9 kmshallow crustal
Coordinates17.945°, -66.948°
Felt byNo felt reports
Status✓ Reviewed by USGS

On September 19, 2026 at 05:06 UTC, a magnitude 3.1 shallow crustal earthquake struck 5 km SW of Guánica, Puerto Rico, at a depth of 7.9 km and coordinates 17.9445°, -66.9478°.

Physical scale: An earthquake of magnitude 3.1 releases seismic energy equivalent to roughly 747 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 87 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 17.94°, -66.95°

Earthquake Details

Magnitude
3.1 md
Depth
7.9 km
shallow crustal
Location
17.9445°N
-66.9478°E

Technical Information

Event ID
pr71532883
Event Type
earthquake
Status
✓ Reviewed
Significance
151
Stations Used
13
Azimuthal Gap
188.0°
Min Station Distance
0.072°
RMS Residual
0.17 sec
Last Updated
2026-09-19 07:22:37 UTC

Common Questions

How strong was the magnitude 3.1 earthquake near Guánica, Puerto Rico?

The magnitude 3.1 earthquake that struck 5 km SW of Guánica, Puerto Rico on September 19, 2026 at 05:06 UTC had a depth of 7.9 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 3.1 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.1 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: pr71532883). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, September 19, 2026). M3.1 Earthquake 5 km SW of Guánica, Puerto RicoSeptember 19, 2026. Retrieved September 19, 2026 from https://www.earthquaketracker.org/earthquakes/event/pr71532883/