QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1md

Earthquake near Luquillo, PR

No earthquake was likely felt in Luquillo in the 24 hours to 2:29 am AST (06:29 UTC). The last one was M 4.1, 61 km (38 mi) SE, at 5:44 am AST on 28 October 2026, estimated intensity II (weak) in town; 5 felt reports to USGS. Every earthquake near Luquillo

This page: a magnitude 3.1 earthquake was recorded 50 km (31 mi) north-northeast of Luquillo, PR, at 10:45 am AST on 4 October 2025 (14:45 UTC), 6.3 km deep.

USGS: 49 km NNE of Vieques, Puerto Rico

67 km (42 mi) NE of San Juan, PR

10:45 am AST, Oct 4, 2025 · · 6.3 km deep · released about 1,300 lb of TNT

Every earthquake near Luquillo Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Fajardo Municipio 46 kmLuquillo Municipio 50 kmRío Grande Municipio 52 kmLoíza Municipio 55 kmCulebra Municipio 60 kmCarolina Municipio 61 kmCeiba Municipio 61 kmCanóvanas Municipio 61 kmSan Juan Municipio 67 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
10:45 am AST on 4 October 2025 ()
Where
50 km (31 mi) north-northeast of Luquillo, PR · earthquakes near Luquillo
Magnitude
M 3.1 (md)
Depth
6.3 km below the surface
Felt
no reports yet
Nearest
Fajardo Municipio, 46 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 327 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 40 km (25 mi) from the epicentre. In Luquillo, 50 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

How big was it?

This earthquake released about 1,300 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 270,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 12,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 8,500× the energy of this one
  4. This earthquake M 3.1 about 1,300 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.3× more

Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.

For this area

The largest earthquake within 50 km since 2016 was M 4.8 on 2021-03-09 — about 380 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.0 73 km NNE of Vieques, Puerto Rico · 24 km NNE of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 18.7998, -65.5783. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Fajardo Municipio, PR 46 km (29 mi) S earthquakes near Fajardo Municipio
Luquillo Municipio, PR 50 km (31 mi) SSW earthquakes near Luquillo Municipio
Río Grande Municipio, PR 52 km (33 mi) SSW earthquakes near Río Grande Municipio
Loíza Municipio, PR 55 km (34 mi) SW earthquakes near Loíza Municipio
Culebra Municipio, PR 60 km (37 mi) SSE earthquakes near Culebra Municipio
Carolina Municipio, PR 61 km (38 mi) SW earthquakes near Carolina Municipio

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

38 earthquakes have been recorded within 50 km since this one.

  1. 3.2 51 km NNE of Vieques, Puerto Rico
  2. 3.1 73 km N of Culebra, Puerto Rico
  3. 3.4 93 km N of Culebra, Puerto Rico
  4. 3.3 20 km NE of Luquillo, Puerto Rico
  5. 3.4 84 km NNE of Vieques, Puerto Rico
  6. 2.5 27 km NNE of Vieques, Puerto Rico
  7. 3.2 76 km N of Culebra, Puerto Rico
  8. 3.4 49 km N of Suárez, Puerto Rico
  9. 3.1 59 km N of Loíza, Puerto Rico
  10. 3.8 30 km NNE of Luquillo, Puerto Rico
  11. 2.9 59 km N of Culebra, Puerto Rico
  12. 2.8 8 km NE of Vieques, Puerto Rico
  13. 3.0 47 km NNE of Vieques, Puerto Rico
  14. 3.4 70 km N of Culebra, Puerto Rico
  15. 3.1 39 km N of Loíza, Puerto Rico

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.