QuakeIndex

Earthquake · reviewed by a seismologist

M 3.5md

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 3.5 earthquake was recorded 18 km (11 mi) northeast of Culebra, PR, at 3:46 pm AST on 25 July 2021 (19:46 UTC), 23 km deep. 8 people have reported feeling it to USGS.

USGS: 18 km NE of Culebra, Puerto Rico

96 km (59 mi) E of San Juan, PR

3:46 pm AST, Jul 25, 2021 · · 23 km deep · released about 2.4 tons of TNT

Every earthquake near Culebra Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Culebra Municipio 18 kmVieques Municipio 42 kmFajardo Municipio 46 kmCeiba Municipio 51 kmLuquillo Municipio 58 kmNaguabo Municipio 64 kmRío Grande Municipio 68 kmHumacao Municipio 73 kmCanóvanas Municipio 77 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
3:46 pm AST on 25 July 2021 ()
Where
18 km (11 mi) northeast of Culebra, PR · earthquakes near Culebra
Magnitude
M 3.5 (md)
Depth
23 km below the surface
Felt
8 reports · strongest reported intensity III
Nearest
Culebra Municipio, 18 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1866 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 57 km (35 mi) from the epicentre. In Culebra, 18 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.

Likely felt in: Culebra 18 km, intensity II · Isabel Segunda 41 km, intensity II · Esperanza 47 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 2.4 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.5 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 70,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 3,100× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,200× the energy of this one
  4. This earthquake M 3.5 about 2.4 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 5.1× 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 4.2 on 2019-07-28 — about 13 times the energy of this one.

Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.

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 18.3968, -65.1570. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Culebra Municipio, PR 18 km (11 mi) WSW earthquakes near Culebra Municipio
Vieques Municipio, PR 42 km (26 mi) SW earthquakes near Vieques Municipio
Fajardo Municipio, PR 46 km (28 mi) W earthquakes near Fajardo Municipio
Ceiba Municipio, PR 51 km (32 mi) WSW earthquakes near Ceiba Municipio
Luquillo Municipio, PR 58 km (36 mi) W earthquakes near Luquillo Municipio
Naguabo Municipio, PR 64 km (40 mi) WSW earthquakes near Naguabo Municipio

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

Aftershocks so far

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

  1. 3.4 31 km N of Charlotte Amalie, U.S. Virgin Islands
  2. 3.1 10 km E of Culebra, Puerto Rico
  3. 3.3 Virgin Islands
  4. 2.8 34 km NNW of Charlotte Amalie, U.S. Virgin Islands
  5. 2.9 13 km SE of Esperanza, Puerto Rico
  6. 2.9 28 km SSW of Charlotte Amalie, U.S. Virgin Islands
  7. 3.7 27 km S of Charlotte Amalie, U.S. Virgin Islands
  8. 3.5 28 km NNE of Culebra, Puerto Rico
  9. 3.5 32 km NNW of Charlotte Amalie, U.S. Virgin Islands
  10. 3.1 21 km WNW of Charlotte Amalie, U.S. Virgin Islands
  11. 2.3 1 km WNW of Esperanza, Puerto Rico
  12. 3.5 34 km N of Culebra, Puerto Rico
  13. 3.0 10 km NNW of Cruz Bay, U.S. Virgin Islands
  14. 3.1 9 km WSW of Culebra, Puerto Rico
  15. 3.2 50 km N of Culebra, 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.