QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9md

Earthquake near Culebra, PR

Yes: an earthquake was likely felt in Culebra in the last 24 hours. M 2.9, 25 km (15 mi) ENE of Culebra, at 6:51 am AST on 11 November 2026 (10:51 UTC); the estimated shaking in Culebra was intensity II (weak). Every earthquake near Culebra

This page: a magnitude 3.9 earthquake was recorded 19 km (12 mi) southeast of Culebra, PR, at 9:34 am AST on 29 July 2023 (13:34 UTC), 135 km deep. 1 person has reported feeling it to USGS.

USGS: 18 km SE of Culebra, Puerto Rico

97 km (60 mi) ESE of San Juan, PR

9:34 am AST, Jul 29, 2023 · · 135 km deep · released about 9.3 tons of TNT

Every earthquake near Culebra Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Culebra Municipio 21 kmVieques Municipio 28 kmCeiba Municipio 47 kmFajardo Municipio 49 kmNaguabo Municipio 59 kmLuquillo Municipio 60 kmHumacao Municipio 65 kmRío Grande Municipio 69 kmLas Piedras Municipio 73 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
9:34 am AST on 29 July 2023 ()
Where
19 km (12 mi) southeast of Culebra, PR · earthquakes near Culebra
Magnitude
M 3.9 (md)
Depth
135 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Culebra Municipio, 21 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1138 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 it was probably too small to be felt, even directly above it. In Culebra, 19 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.

Earthquakes near other towns within 30 km: Isabel Segunda.

How big was it?

This earthquake released about 9.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.9 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 18,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 810× the energy of this one
  3. Magna, Utah 2020 M 5.7 580× the energy of this one
  4. This earthquake M 3.9 about 9.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 19× 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 2021-10-08 — about 26 times the energy of this one.

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

  1. 5.0 29 km S of Cruz Bay, U.S. Virgin Islands · 46 km ESE 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 18.1823, -65.1776. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Culebra Municipio, PR 21 km (13 mi) NW earthquakes near Culebra Municipio
Vieques Municipio, PR 28 km (17 mi) WSW earthquakes near Vieques Municipio
Ceiba Municipio, PR 47 km (29 mi) W earthquakes near Ceiba Municipio
Fajardo Municipio, PR 49 km (30 mi) WNW earthquakes near Fajardo Municipio
Naguabo Municipio, PR 59 km (37 mi) W earthquakes near Naguabo Municipio
Luquillo Municipio, PR 60 km (37 mi) WNW earthquakes near Luquillo Municipio

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

Aftershocks so far

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

  1. 3.5 11 km SSE of Daguao, Puerto Rico
  2. 3.4 14 km SE of Esperanza, Puerto Rico
  3. 3.2 17 km SE of Esperanza, Puerto Rico
  4. 2.9 14 km SE of Esperanza, Puerto Rico
  5. 3.2 19 km SSE of Esperanza, Puerto Rico
  6. 3.0 14 km SE of Esperanza, Puerto Rico
  7. 3.0 15 km SE of Esperanza, Puerto Rico
  8. 3.6 17 km SE of Esperanza, Puerto Rico
  9. 3.4 14 km SE of Esperanza, Puerto Rico
  10. 2.9 14 km SE of Esperanza, Puerto Rico
  11. 2.5 32 km NNW of Charlotte Amalie, U.S. Virgin Islands
  12. 2.7 10 km SSE of Esperanza, Puerto Rico
  13. 3.6 10 km SW of Cruz Bay, U.S. Virgin Islands
  14. 3.2 11 km S of Esperanza, Puerto Rico
  15. 3.0 16 km SE of Esperanza, 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.