QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9md

91 km N of Charlotte Amalie, U.S. Virgin Islands

· 42 km deep · released about 9.3 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Culebra Municipio 100 kmFajardo Municipio 108 kmLuquillo Municipio 117 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
42 km below the surface
Felt
no reports yet
Nearest
Culebra Municipio, 100 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 897 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

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 19.1705, -64.9898. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Culebra Municipio, PR 100 km (62 mi) NNE of here earthquakes near Culebra Municipio
Fajardo Municipio, PR 108 km (67 mi) NE of here earthquakes near Fajardo Municipio
Luquillo Municipio, PR 117 km (73 mi) NE of here earthquakes near Luquillo Municipio
Ceiba Municipio, PR 122 km (76 mi) NNE of here earthquakes near Ceiba Municipio
Río Grande Municipio, PR 123 km (76 mi) NE of here earthquakes near Río Grande Municipio
Vieques Municipio, PR 125 km (78 mi) NNE of here earthquakes near Vieques 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. 3.5 103 km N of Culebra, Puerto Rico
  2. 3.4 97 km NNE of Cruz Bay, U.S. Virgin Islands
  3. 3.8 99 km N of Cruz Bay, U.S. Virgin Islands
  4. 3.8 101 km N of Cruz Bay, U.S. Virgin Islands
  5. 3.7 101 km N of Charlotte Amalie, U.S. Virgin Islands
  6. 3.6 106 km N of Charlotte Amalie, U.S. Virgin Islands
  7. 3.6 90 km NNE of Vieques, Puerto Rico
  8. 3.3 68 km N of Culebra, Puerto Rico
  9. 3.4 56 km N of Culebra, Puerto Rico
  10. 3.2 59 km N of Culebra, Puerto Rico
  11. 3.5 95 km N of Charlotte Amalie, U.S. Virgin Islands
  12. 3.8 107 km N of Cruz Bay, U.S. Virgin Islands
  13. 3.6 91 km N of Culebra, Puerto Rico
  14. 3.5 55 km N of Cruz Bay, U.S. Virgin Islands
  15. 3.8 54 km NNE 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.

For this area

The largest earthquake within 50 km in our catalogue was M 5.0 on 2021-02-06 — it released about 50 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.