QuakeIndex

Earthquake · reviewed by a seismologist

M 4.2ml

18 km NNW of Charlotte Amalie, U.S. Virgin Islands

Yes. A magnitude 4.2 earthquake was recorded 18 km NNW of Charlotte Amalie, U.S. Virgin Islands, at 5:41 pm AST on 28 July 2019 (21:41 UTC), 13 km deep. 153 people have reported feeling it to USGS.

· 13 km deep · released about 32 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Culebra Municipio 38 kmVieques Municipio 62 kmFajardo Municipio 64 kmCeiba Municipio 71 kmLuquillo Municipio 77 kmNaguabo Municipio 84 kmRío Grande Municipio 86 kmHumacao Municipio 93 kmCanóvanas Municipio 96 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 (ml)
Depth
13 km below the surface
Felt
153 reports · strongest reported intensity IV
Nearest
Culebra Municipio, 38 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2588 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 113 km (70 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 39 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 32 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 5,200× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 230× the energy of this one
  3. Magna, Utah 2020 M 5.7 170× the energy of this one
  4. This earthquake M 4.2 about 32 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 68× 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 4.7 on 2018-04-06 — about 5.2 times the energy of this one.

Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:

  1. 5.2 36 km NNE of Cruz Bay, U.S. Virgin Islands · 35 km ENE of this epicentre
  2. 5.0 40 km NNE of Cruz Bay, U.S. Virgin Islands · 42 km ENE 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 18.4970, -64.9950. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Culebra Municipio, PR 38 km (24 mi) WSW earthquakes near Culebra Municipio
Vieques Municipio, PR 62 km (39 mi) SW earthquakes near Vieques Municipio
Fajardo Municipio, PR 64 km (40 mi) W earthquakes near Fajardo Municipio
Ceiba Municipio, PR 71 km (44 mi) WSW earthquakes near Ceiba Municipio
Luquillo Municipio, PR 77 km (48 mi) W earthquakes near Luquillo Municipio
Naguabo Municipio, PR 84 km (52 mi) WSW earthquakes near Naguabo Municipio

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

Aftershocks so far

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

  1. 3.1 17 km NNW of Charlotte Amalie, U.S. Virgin Islands
  2. 2.4 20 km SSW of Charlotte Amalie, U.S. Virgin Islands
  3. 2.7 33 km NNW of Charlotte Amalie, U.S. Virgin Islands
  4. 3.2 Puerto Rico region
  5. 2.6 21 km N of Charlotte Amalie, U.S. Virgin Islands
  6. 3.1 62 km N of Charlotte Amalie, U.S. Virgin Islands
  7. 2.4 52 km N of Culebra, Puerto Rico
  8. 2.8 65 km NNW of Charlotte Amalie, U.S. Virgin Islands
  9. 2.6 43 km NNW of Charlotte Amalie, U.S. Virgin Islands
  10. 2.3 23 km NNW of Charlotte Amalie, U.S. Virgin Islands
  11. 3.1 52 km NNE of Culebra, Puerto Rico
  12. 2.1 28 km NW of Culebra, Puerto Rico
  13. 3.1 19 km E of Cruz Bay, U.S. Virgin Islands
  14. 3.1 18 km ESE of Cruz Bay, U.S. Virgin Islands
  15. 2.3 57 km N 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.

On USGS

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