M1.9 earthquake 8 km ESE of Guánica, Puerto Rico
A magnitude 1.9 earthquake struck 8 km ESE of Guánica, Puerto Rico at 00:47 local time (04:47 UTC) on 4 Oct 2026, at a depth of 16 km, according to USGS.
Data: USGS · updated 2026-10-04 05:29 UTC · reviewed
- Magnitude
- 1.9micro
duration magnitude (md) - Depth
- 16 km
- Status
- Reviewed
- Origin time
- 2026-10-04 04:47:10 UTC
- Local: 4 Oct 2026, 00:47:10 (America/Puerto Rico)
- Epicentre
- 17.951° N, 66.835° 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 |
|---|---|---|
| GuánicaPuerto Rico · pop. 9,224 | 8 km | INot felt |
| YaucoPuerto Rico · pop. 20,295 | 9 km | INot felt |
| PoncePuerto Rico · pop. 137,491 | 24 km | INot felt |
| MayagüezPuerto Rico · pop. 73,077 | 43 km | INot felt |
| AreciboPuerto Rico · pop. 87,754 | 59 km | INot felt |
| San JuanPuerto Rico · pop. 418,140 | 96 km | INot felt |
| Santo Domingo EsteSanto Domingo Province, Dominican Republic · pop. 700,000 | 324 km | INot felt |
| Santo DomingoNacional, Dominican Republic · pop. 2,201,941 | 328 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 | 1.9 md | 16 km | 17.95° N, 66.83° W | – | Reviewed |
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How big was it?
Usually not felt. Recorded by nearby seismometers; thousands occur worldwide every day.
It released roughly the energy of 10 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 16 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.
M1.9 releases about 21× the energy of M1.0, and its waves are about 7.6× taller on a seismogram. Energy: 10 kg of TNT vs 477 g of TNT.
Each square is the energy of one M1.0. Energy from log₁₀E = 1.5M + 4.8.
Aftershocks and nearby activity
1 later earthquake within 30 km; the largest was M2.2 1 h 38 min ago. 26 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.
Mainshock M1.9
1 later earthquake nearby. Aftershock rates typically fall off roughly as 1/time (Omori's law).
| Time after mainshock (hours) | Magnitude | Depth (km) |
|---|---|---|
| 0.56 | 2.2 | 8 |
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.
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Event id pr71535648. First recorded here 4 Oct 2026, 05:30:54 UTC. Solutions: USGS · PR (usgs:pr71535648). Cite as: SeismoAtlas, “M1.9 earthquake 8 km ESE of Guánica, Puerto Rico”, https://seismoatlas.com/earthquake/pr71535648-m1-9-earthquake-8-km-ese-of-guanica-puerto-rico, data from USGS.
JSON: /api/v1/events/pr71535648. SeismoAtlas is not an official warning service.