QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9md

50 km NNE of Cruz Bay, U.S. Virgin Islands

· 30 km deep · released about 9 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Culebra Municipio 88 kmFajardo Municipio 112 kmVieques Municipio 112 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
30 km below the surface
Felt
50 reports · strongest reported intensity III
Nearest
Culebra Municipio, 88 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2164 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 50 people have reported feeling it to USGS.

How big was it?

This earthquake released about 9 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.8 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 19,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 840× the energy of this one
  3. Magna, Utah 2020 M 5.7 600× the energy of this one
  4. This earthquake M 3.9 about 9 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 18.7450, -64.6005. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Culebra Municipio, PR 88 km (55 mi) ENE of here earthquakes near Culebra Municipio
Fajardo Municipio, PR 112 km (69 mi) ENE of here earthquakes near Fajardo Municipio
Vieques Municipio, PR 112 km (69 mi) NE of here earthquakes near Vieques Municipio
Ceiba Municipio, PR 121 km (75 mi) ENE of here earthquakes near Ceiba Municipio
Luquillo Municipio, PR 124 km (77 mi) ENE of here earthquakes near Luquillo Municipio
Naguabo Municipio, PR 134 km (83 mi) ENE of here earthquakes near Naguabo Municipio

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

Aftershocks so far

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

  1. 3.4 31 km N of Charlotte Amalie, U.S. Virgin Islands
  2. 3.4 41 km NE of Cruz Bay, U.S. Virgin Islands
  3. 3.5 59 km N of Charlotte Amalie, U.S. Virgin Islands
  4. 3.4 83 km N of Charlotte Amalie, U.S. Virgin Islands
  5. 3.3 87 km N of Charlotte Amalie, U.S. Virgin Islands
  6. 3.4 66 km N of Cruz Bay, U.S. Virgin Islands
  7. 3.4 74 km NE of Cruz Bay, U.S. Virgin Islands
  8. 3.4 79 km N of Charlotte Amalie, U.S. Virgin Islands
  9. 3.2 58 km N of Cruz Bay, U.S. Virgin Islands
  10. 3.1 56 km NNE of Cruz Bay, U.S. Virgin Islands
  11. 3.7 50 km N of Charlotte Amalie, U.S. Virgin Islands
  12. 3.5 71 km ENE of Cruz Bay, U.S. Virgin Islands
  13. 3.9 67 km NNE of Cruz Bay, U.S. Virgin Islands
  14. 3.4 88 km NE of Cruz Bay, U.S. Virgin Islands
  15. 3.4 47 km NNE 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.7 on 2018-04-06 — it released about 19 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.