M3.9 earthquake 20 km NW of Rincón, Puerto Rico
A magnitude 3.9 earthquake struck 20 km NW of Rincón, Puerto Rico at 06:35 local time (10:35 UTC) on 3 Oct 2026, at a depth of 6 km, according to USGS.
9 reports to USGS “Did You Feel It?”
Data: USGS · updated 2026-10-03 11:26 UTC · reviewed
- Magnitude
- 3.9minor
duration magnitude (md) - Depth
- 6 km
- Status
- Reviewed
- Origin time
- 2026-10-03 10:35:38 UTC
- Local: 3 Oct 2026, 06:35:38 (America/Puerto Rico)
- Epicentre
- 18.446° N, 67.398° W
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Circles show this event and others within 30 km from 7 days before to 30 days after. Lines: plate boundaries and GEM active faults. Open on the live map
Nearby places
| Place | Distance | Est. shaking |
|---|---|---|
| RincónPuerto Rico · pop. 1,499 | 20 km | IIIWeak |
| AguadaPuerto Rico · pop. 4,040 | 23 km | IIIWeak |
| MayagüezPuerto Rico · pop. 73,077 | 39 km | IIWeak |
| AreciboPuerto Rico · pop. 87,754 | 72 km | IIWeak |
| YaucoPuerto Rico · pop. 20,295 | 74 km | IIWeak |
| BarcelonetaPuerto Rico · pop. 22,322 | 90 km | INot felt |
| San JuanPuerto Rico · pop. 418,140 | 136 km | INot felt |
| Santo Domingo EsteSanto Domingo Province, Dominican Republic · pop. 700,000 | 259 km | INot felt |
Shaking is an estimate from the intensity prediction equation of Allen, Wald & Worden (2012), not an observation. Local ground and buildings can change it by a level or more. Likely felt out to about 37 km.
Every agency's solution
Agencies locate earthquakes with their own stations and methods, so their numbers differ. We match reports of the same event by time, distance and magnitude and show them side by side. The headline uses USGS · PR, which has been reviewed by an analyst.
| Agency | Magnitude | Depth | Epicentre | Time offset | Status |
|---|---|---|---|---|---|
| USGS · PRheadlinePuerto Rico Seismic Network via U.S. Geological Survey | 3.9 mdwas 3.9 | 6 km | 18.45° N, 67.40° W | – | Reviewed · 1 revision |
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How big was it?
Often felt by people at rest close to the epicentre, rarely causes damage.
It released roughly the energy of 9 t of TNT. Magnitude is logarithmic: each whole step means about 32 times more energy and 10 times larger waves on a seismogram. Depth matters too: at 6 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.
M3.9 releases about 27× the energy of M2.9, and its waves are about 8.9× taller on a seismogram. Energy: 9 t of TNT vs 338 kg of TNT.
Each square is the energy of one M2.9. Energy from log₁₀E = 1.5M + 4.8.
Aftershocks and nearby activity
No later earthquakes have been recorded within 30 km so far. Aftershock rates usually fall off roughly in proportion to 1/time.
Did you feel it?
Reports from people help show where shaking was strong. They are anonymous and shown here in aggregate.
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Event id us6000tzc3. First recorded here 3 Oct 2026, 10:45:08 UTC. Solutions: USGS · PR (usgs:pr2026276000). Cite as: SeismoAtlas, “M3.9 earthquake 20 km NW of Rincón, Puerto Rico”, https://seismoatlas.com/earthquake/us6000tzc3-m3-9-earthquake-20-km-nw-of-rincon-puerto-rico, data from USGS.
JSON: /api/v1/events/us6000tzc3. SeismoAtlas is not an official warning service.