QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3md

14 km SW of Saint Croix, U.S. Virgin Islands

Yes. A magnitude 3.3 earthquake was recorded 14 km SW of Saint Croix, U.S. Virgin Islands, at 4:33 am AST on 23 September 2024 (08:33 UTC), 45 km deep.

· 45 km deep · released about 1.2 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Vieques Municipio 83 kmCulebra Municipio 92 kmCeiba Municipio 108 kmNaguabo Municipio 115 kmHumacao Municipio 115 kmFajardo Municipio 115 kmYabucoa Municipio 118 kmMaunabo Municipio 119 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 3.3 (md)
Depth
45 km below the surface
Felt
no reports yet
Nearest
Vieques Municipio, 83 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 780 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 22 km (14 mi) from the epicentre. 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 1.2 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 140,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 6,500× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,600× the energy of this one
  4. This earthquake M 3.3 about 1.2 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.5× 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:

  1. 6.1 22 km NNE of Saint Croix, U.S. Virgin Islands · 37 km NE of this epicentre
  2. 5.0 29 km S of Cruz Bay, U.S. Virgin Islands · 49 km N 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 17.6333, -64.8390. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Vieques Municipio, PR 83 km (52 mi) NW earthquakes near Vieques Municipio
Culebra Municipio, PR 92 km (57 mi) NNW earthquakes near Culebra Municipio
Ceiba Municipio, PR 108 km (67 mi) NW earthquakes near Ceiba Municipio
Naguabo Municipio, PR 115 km (71 mi) NW earthquakes near Naguabo Municipio
Humacao Municipio, PR 115 km (71 mi) WNW earthquakes near Humacao Municipio
Fajardo Municipio, PR 115 km (72 mi) NW earthquakes near Fajardo Municipio

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

Aftershocks so far

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

  1. 2.6 23 km NNW of Saint Croix, U.S. Virgin Islands
  2. 3.2 40 km SE of Esperanza, Puerto Rico
  3. 3.6 33 km NNW of Saint Croix, U.S. Virgin Islands
  4. 3.2 35 km SE of Esperanza, Puerto Rico
  5. 3.2 54 km WSW of Saint Croix, U.S. Virgin Islands
  6. 3.1 30 km SSE of Saint Croix, U.S. Virgin Islands
  7. 3.1 18 km NW of Saint Croix, U.S. Virgin Islands
  8. 3.1 7 km S of Saint Croix, U.S. Virgin Islands
  9. 2.8 41 km SE of Esperanza, Puerto Rico
  10. 2.7 22 km NNE of Christiansted, U.S. Virgin Islands
  11. 3.4 38 km SSW of Saint Croix, U.S. Virgin Islands
  12. 3.1 36 km SSW of Saint Croix, U.S. Virgin Islands
  13. 3.4 20 km SSW of Saint Croix, U.S. Virgin Islands
  14. 3.1 22 km NNE of Christiansted, U.S. Virgin Islands
  15. 3.2 31 km NW of Saint Croix, 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.