QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9md

96 km N of Cruz Bay, U.S. Virgin Islands

· 31 km deep · released about 10 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Culebra 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
31 km below the surface
Felt
1 report · strongest reported intensity I
Nearest
Culebra Municipio, 117 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1984 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 1 person has reported feeling it to USGS.

How big was it?

This earthquake released about 10 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 16,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 730× the energy of this one
  3. Magna, Utah 2020 M 5.7 520× the energy of this one
  4. This earthquake M 3.9 about 10 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 22× 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 19.1938, -64.6816. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Culebra Municipio, PR 117 km (73 mi) NE of here earthquakes near Culebra Municipio
Fajardo Municipio, PR 131 km (81 mi) NE of here earthquakes near Fajardo Municipio
Luquillo Municipio, PR 142 km (88 mi) NE of here earthquakes near Luquillo Municipio
Vieques Municipio, PR 143 km (89 mi) NNE of here earthquakes near Vieques Municipio
Ceiba Municipio, PR 144 km (89 mi) NE of here earthquakes near Ceiba Municipio
Río Grande Municipio, PR 149 km (92 mi) NE of here earthquakes near Río Grande Municipio

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

Aftershocks so far

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

  1. 3.4 112 km N of Charlotte Amalie, U.S. Virgin Islands
  2. 3.4 82 km N of Cruz Bay, U.S. Virgin Islands
  3. 3.4 116 km N of Charlotte Amalie, U.S. Virgin Islands
  4. 3.6 88 km N of Charlotte Amalie, U.S. Virgin Islands
  5. 4.0 124 km N of Charlotte Amalie, U.S. Virgin Islands
  6. 3.5 100 km N of Charlotte Amalie, U.S. Virgin Islands
  7. 3.6 89 km N of Charlotte Amalie, U.S. Virgin Islands
  8. 3.8 93 km NNE of Cruz Bay, U.S. Virgin Islands
  9. 3.7 92 km N of Charlotte Amalie, U.S. Virgin Islands
  10. 3.5 96 km N of Cruz Bay, U.S. Virgin Islands
  11. 3.7 83 km N of Cruz Bay, U.S. Virgin Islands
  12. 3.6 106 km N of Cruz Bay, U.S. Virgin Islands
  13. 3.6 77 km N of Charlotte Amalie, U.S. Virgin Islands
  14. 3.8 89 km N of Charlotte Amalie, U.S. Virgin Islands
  15. 3.3 63 km N of Charlotte Amalie, 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 5.0 on 2021-02-06 — it released about 45 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.