QuakeIndex

Earthquake · reviewed by a seismologist

M 4.0md

12 km S of Cruz Bay, U.S. Virgin Islands

Yes. A magnitude 4.0 earthquake was recorded 12 km S of Cruz Bay, U.S. Virgin Islands, at 4:10 am AST on 24 October 2023 (08:10 UTC), 116 km deep.

· 116 km deep · released about 15 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Culebra Municipio 58 kmVieques Municipio 71 kmFajardo Municipio 88 kmCeiba Municipio 90 kmLuquillo Municipio 100 kmNaguabo Municipio 102 kmHumacao Municipio 108 kmRío Grande Municipio 110 kmLas Piedras Municipio 116 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 4.0 (md)
Depth
116 km below the surface
Felt
no reports yet
Nearest
Culebra Municipio, 58 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1042 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth it was probably too small to be felt, even directly above it. 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 15 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 11,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 500× the energy of this one
  3. Magna, Utah 2020 M 5.7 350× the energy of this one
  4. This earthquake M 4.0 about 15 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 32× 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 4.4 on 2022-09-03 — about 4.4 times the energy of this one.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

  1. 6.1 22 km NNE of Saint Croix, U.S. Virgin Islands · 39 km SSE of this epicentre
  2. 5.2 36 km NNE of Cruz Bay, U.S. Virgin Islands · 48 km N of this epicentre
  3. 5.0 29 km S of Cruz Bay, U.S. Virgin Islands · 17 km S 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 18.2245, -64.7723. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Culebra Municipio, PR 58 km (36 mi) WNW earthquakes near Culebra Municipio
Vieques Municipio, PR 71 km (44 mi) W earthquakes near Vieques Municipio
Fajardo Municipio, PR 88 km (55 mi) WNW earthquakes near Fajardo Municipio
Ceiba Municipio, PR 90 km (56 mi) W earthquakes near Ceiba Municipio
Luquillo Municipio, PR 100 km (62 mi) W earthquakes near Luquillo Municipio
Naguabo Municipio, PR 102 km (63 mi) W earthquakes near Naguabo 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. 3.2 13 km ESE of Cruz Bay, U.S. Virgin Islands
  2. 3.4 28 km NNE of Cruz Bay, U.S. Virgin Islands
  3. 3.0 24 km ENE of Cruz Bay, U.S. Virgin Islands
  4. 3.6 27 km N of Charlotte Amalie, U.S. Virgin Islands
  5. 3.4 8 km NNE of Cruz Bay, U.S. Virgin Islands
  6. 2.6 32 km N of Charlotte Amalie, U.S. Virgin Islands
  7. 3.1 37 km NNE of Cruz Bay, U.S. Virgin Islands
  8. 2.7 27 km S of Charlotte Amalie, U.S. Virgin Islands
  9. 3.4 22 km SSW of Cruz Bay, U.S. Virgin Islands
  10. 3.4 15 km ESE of Cruz Bay, U.S. Virgin Islands
  11. 3.4 31 km N of Charlotte Amalie, U.S. Virgin Islands
  12. 2.9 19 km ENE of Cruz Bay, U.S. Virgin Islands
  13. 2.9 26 km NNW of Charlotte Amalie, U.S. Virgin Islands
  14. 3.1 23 km SE of Culebra, Puerto Rico
  15. 3.3 19 km NE of Cruz Bay, U.S. Virgin Islands

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.