QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9md

18 km SE of Culebra, Puerto Rico

· 135 km deep · released about 9.3 tons of TNT

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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
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 1093 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 1 person has reported feeling it to USGS.

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.

Where

Epicentre 18.1823, -65.1776. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Culebra Municipio, PR 21 km (13 mi) SE of here earthquakes near Culebra Municipio
Vieques Municipio, PR 28 km (17 mi) ENE of here earthquakes near Vieques Municipio
Ceiba Municipio, PR 47 km (29 mi) E of here earthquakes near Ceiba Municipio
Fajardo Municipio, PR 49 km (30 mi) ESE of here earthquakes near Fajardo Municipio
Naguabo Municipio, PR 59 km (37 mi) E of here earthquakes near Naguabo Municipio
Luquillo Municipio, PR 60 km (37 mi) ESE of here 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.8 on 2021-10-08 — it released about 26 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

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