QuakeIndex

Earthquake · reviewed by a seismologist

M 4.2mb

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

Yes. A magnitude 4.2 earthquake was recorded 48 km N of Charlotte Amalie, U.S. Virgin Islands, at 7:45 pm AST on 7 January 2018 (23:45 UTC), 35 km deep. 2 people have reported feeling it to USGS.

· 35 km deep · released about 30 tons of TNT

10 km30 km60 km120 km N Culebra Municipio 61 kmFajardo Municipio 78 kmVieques Municipio 87 kmCeiba Municipio 90 kmLuquillo Municipio 90 kmRío Grande Municipio 98 kmNaguabo Municipio 102 kmCanóvanas Municipio 108 kmLoíza Municipio 109 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 4.2 (mb)
Depth
35 km below the surface
Felt
2 reports · strongest reported intensity III
Nearest
Culebra Municipio, 61 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3155 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth, people at rest would likely notice it out to about 107 km (66 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 30 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 5,600× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 250× the energy of this one
  3. Magna, Utah 2020 M 5.7 180× the energy of this one
  4. This earthquake M 4.2 about 30 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 63× 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 (31 mi) since our catalogue begins in 2016. The previous largest was M 4.0 on 2016-06-29.

Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.1 91 km N of Charlotte Amalie, U.S. Virgin Islands · 45 km NNE of this epicentre
  2. 5.9 68 km N of Cruz Bay, U.S. Virgin Islands · 34 km NE of this epicentre
  3. 5.9 65 km NNE of Cruz Bay, U.S. Virgin Islands · 43 km ENE of this epicentre
  4. 5.7 80 km NNE of Cruz Bay, U.S. Virgin Islands · 50 km ENE of this epicentre
  5. 5.3 78 km NNE of Cruz Bay, U.S. Virgin Islands · 45 km NE 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 18.7780, -64.9717. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Culebra Municipio, PR 61 km (38 mi) SW earthquakes near Culebra Municipio
Fajardo Municipio, PR 78 km (49 mi) WSW earthquakes near Fajardo Municipio
Vieques Municipio, PR 87 km (54 mi) SW earthquakes near Vieques Municipio
Ceiba Municipio, PR 90 km (56 mi) SW earthquakes near Ceiba Municipio
Luquillo Municipio, PR 90 km (56 mi) WSW earthquakes near Luquillo Municipio
Río Grande Municipio, PR 98 km (61 mi) WSW earthquakes near Río Grande Municipio

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

Aftershocks so far

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

  1. 4.1 55 km NNE of Cruz Bay, U.S. Virgin Islands
  2. 3.4 37 km N of Cruz Bay, U.S. Virgin Islands
  3. 3.3 31 km NW of Charlotte Amalie, U.S. Virgin Islands
  4. 3.3 84 km N of Cruz Bay, U.S. Virgin Islands
  5. 3.4 19 km NNE of Cruz Bay, U.S. Virgin Islands
  6. 3.4 46 km NNW of Charlotte Amalie, U.S. Virgin Islands
  7. 3.2 64 km N of Cruz Bay, U.S. Virgin Islands
  8. 3.1 93 km N of Charlotte Amalie, U.S. Virgin Islands
  9. 3.3 90 km N of Charlotte Amalie, U.S. Virgin Islands
  10. 3.5 96 km N of Charlotte Amalie, U.S. Virgin Islands
  11. 3.5 55 km N of Charlotte Amalie, U.S. Virgin Islands
  12. 3.4 85 km N of Charlotte Amalie, U.S. Virgin Islands
  13. 3.2 65 km NNW of Charlotte Amalie, U.S. Virgin Islands
  14. 3.4 Virgin Islands
  15. 3.5 44 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.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.