M2.1 earthquake near Guayanilla, Puerto Rico
A magnitude 2.1 earthquake struck near Guayanilla, Puerto Rico at 10:36 local time (14:36 UTC) on 4 Oct 2026, at a depth of 14 km, according to USGS.
Data: USGS · updated 2026-10-04 14:59 UTC · reviewed
- Magnitude
- 2.1micro
duration magnitude (md) - Depth
- 14 km
- Status
- Reviewed
- Origin time
- 2026-10-04 14:36:59 UTC
- Local: 4 Oct 2026, 10:36:59 (America/Puerto Rico)
- Epicentre
- 18.042° N, 66.785° W
Advertisement
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 |
|---|---|---|
| GuayanillaPuerto Rico · pop. 5,213 | 3 km | INot felt |
| YaucoPuerto Rico · pop. 20,295 | 7 km | INot felt |
| PoncePuerto Rico · pop. 137,491 | 18 km | INot felt |
| MayagüezPuerto Rico · pop. 73,077 | 41 km | INot felt |
| AreciboPuerto Rico · pop. 87,754 | 48 km | INot felt |
| San JuanPuerto Rico · pop. 418,140 | 86 km | INot felt |
| Santo Domingo EsteSanto Domingo Province, Dominican Republic · pop. 700,000 | 327 km | INot felt |
| Santo DomingoNacional, Dominican Republic · pop. 2,201,941 | 331 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.
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 | 2.1 md | 14 km | 18.04° N, 66.78° W | – | Reviewed |
Advertisement
How big was it?
Usually not felt. Recorded by nearby seismometers; thousands occur worldwide every day.
It released roughly the energy of 24 kg 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 14 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.
M2.1 releases about 35× the energy of M1.1, and its waves are about 11× taller on a seismogram. Energy: 24 kg of TNT vs 674 g of TNT.
Each square is the energy of one M1.1. Energy from log₁₀E = 1.5M + 4.8.
Aftershocks and nearby activity
16 later earthquakes within 30 km; the largest was M2.8 1 day ago. 24 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.
Mainshock M2.1
16 later earthquakes nearby. Aftershock rates typically fall off roughly as 1/time (Omori's law).
| Time after mainshock (hours) | Magnitude | Depth (km) |
|---|---|---|
| 13.72 | 2.1 | 14 |
| 15.68 | 2.1 | 4 |
| 27.30 | 1.3 | 12 |
| 28.74 | 1.8 | 8 |
| 52.63 | 2.0 | 14 |
| 65.66 | 2.5 | 6 |
| 81.44 | 2.1 | 16 |
| 106.91 | 1.9 | 14 |
| 108.90 | 2.2 | 15 |
| 115.01 | 2.3 | 7 |
| 129.73 | 1.9 | 8 |
| 132.41 | 2.8 | 18 |
| 158.41 | 1.4 | 7 |
| 161.56 | 1.5 | 5 |
| 165.72 | 2.0 | 9 |
| 177.34 | 1.9 | 13 |
- 2.8Near Las Marías, Puerto Rico10-10 03:01
- 2.5Near Guánica, Puerto Rico10-07 08:16
- 2.34 km SW of Guánica, Puerto Rico10-09 09:37
- 2.28 km SSE of Guánica, Puerto Rico10-09 03:30
- 2.112 km WSW of Guánica, Puerto Rico10-05 06:17
- 2.1Near Guánica, Puerto Rico10-05 04:20
- 2.15 km WNW of Yauco, Puerto Rico10-08 00:03
- 2.06 km SSE of Ponce, Puerto Rico10-06 19:14
- 2.0Near Guánica, Puerto Rico10-11 12:20
- 1.99 km SW of Guánica, Puerto Rico10-09 01:31
- 1.9Near Guánica, Puerto Rico10-10 00:20
- 1.99 km W of Guánica, Puerto Rico10-11 23:57
- 1.86 km SE of Sabana Grande, Puerto Rico10-05 19:21
- 1.56 km NNW of Guánica, Puerto Rico10-11 08:10
- 1.44 km NW of Guánica, Puerto Rico10-11 05:01
- 1.38 km W of Guánica, Puerto Rico10-05 17:55
Did you feel it?
Reports from people help show where shaking was strong. They are anonymous and shown here in aggregate.
Reports on SeismoAtlas
No reports yet.
Advertisement
Event id pr71535723. First recorded here 4 Oct 2026, 15:00:15 UTC. Solutions: USGS · PR (usgs:pr71535723). Cite as: SeismoAtlas, “M2.1 earthquake near Guayanilla, Puerto Rico”, https://seismoatlas.com/earthquake/pr71535723-m2-1-earthquake-near-guayanilla-puerto-rico, data from USGS.
JSON: /api/v1/events/pr71535723. SeismoAtlas is not an official warning service.