QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3md

28 km S of Charlotte Amalie, U.S. Virgin Islands

Yes. A magnitude 3.3 earthquake was recorded 28 km S of Charlotte Amalie, U.S. Virgin Islands, at 7:16 pm AST on 7 October 2023 (23:16 UTC), 8.3 km deep.

· 8.3 km deep · released about 1.3 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Culebra Municipio 43 kmVieques Municipio 48 kmCeiba Municipio 70 kmFajardo Municipio 72 kmNaguabo Municipio 81 kmLuquillo Municipio 83 kmHumacao Municipio 85 kmRío Grande Municipio 92 kmYabucoa Municipio 93 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
8.3 km below the surface
Felt
no reports yet
Nearest
Culebra Municipio, 43 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1063 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 51 km (32 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.

Likely felt in: Culebra 41 km, intensity II · Isabel Segunda 49 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1.3 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 6.7 130,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 5,600× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,000× the energy of this one
  4. This earthquake M 3.3 about 1.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.8× 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 180 times the energy of this one.

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 · 42 km ESE of this epicentre
  2. 5.0 29 km S of Cruz Bay, U.S. Virgin Islands · 24 km E 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 18.0927, -64.9812. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Culebra Municipio, PR 43 km (27 mi) NW earthquakes near Culebra Municipio
Vieques Municipio, PR 48 km (30 mi) W earthquakes near Vieques Municipio
Ceiba Municipio, PR 70 km (43 mi) WNW earthquakes near Ceiba Municipio
Fajardo Municipio, PR 72 km (45 mi) WNW earthquakes near Fajardo Municipio
Naguabo Municipio, PR 81 km (50 mi) W earthquakes near Naguabo Municipio
Luquillo Municipio, PR 83 km (51 mi) WNW earthquakes near Luquillo Municipio

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

Aftershocks so far

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

  1. 3.4 8 km NNE of Cruz Bay, U.S. Virgin Islands
  2. 2.7 27 km S of Charlotte Amalie, U.S. Virgin Islands
  3. 3.4 22 km SSW of Cruz Bay, U.S. Virgin Islands
  4. 3.4 15 km ESE of Cruz Bay, U.S. Virgin Islands
  5. 3.2 32 km SE of Esperanza, Puerto Rico
  6. 3.1 23 km SE of Culebra, Puerto Rico
  7. 3.1 18 km S of Cruz Bay, U.S. Virgin Islands
  8. 3.2 24 km SSE of Cruz Bay, U.S. Virgin Islands
  9. 3.0 7 km SE of Esperanza, Puerto Rico
  10. 2.5 10 km SE of Esperanza, Puerto Rico
  11. 2.7 33 km SSE of Esperanza, Puerto Rico
  12. 3.3 22 km SSW of Charlotte Amalie, U.S. Virgin Islands
  13. 3.1 16 km SW of Charlotte Amalie, U.S. Virgin Islands
  14. 3.0 6 km E of Esperanza, Puerto Rico
  15. 3.1 22 km NNE of Christiansted, 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.