QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0md

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

Yes. A magnitude 3.0 earthquake was recorded 18 km S of Charlotte Amalie, U.S. Virgin Islands, at 10:43 am AST on 28 August 2017 (14:43 UTC), 25 km deep.

· 25 km deep · released about 800 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Culebra Municipio 45 kmVieques Municipio 56 kmFajardo Municipio 75 kmCeiba Municipio 76 kmLuquillo Municipio 87 kmNaguabo Municipio 87 kmHumacao Municipio 93 kmRío Grande Municipio 96 kmYabucoa Municipio 101 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 3.0 (md)
Depth
25 km below the surface
Felt
no reports yet
Nearest
Culebra Municipio, 45 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3362 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 23 km (14 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 800 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 420,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 19,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 13,000× the energy of this one
  4. This earthquake M 3.0 about 800 lb of TNT

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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

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

  1. 6.1 22 km NNE of Saint Croix, U.S. Virgin Islands · 42 km SE of this epicentre
  2. 5.0 29 km S of Cruz Bay, U.S. Virgin Islands · 20 km SE 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 18.1783, -64.9096. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Culebra Municipio, PR 45 km (28 mi) WNW earthquakes near Culebra Municipio
Vieques Municipio, PR 56 km (35 mi) W earthquakes near Vieques Municipio
Fajardo Municipio, PR 75 km (47 mi) WNW earthquakes near Fajardo Municipio
Ceiba Municipio, PR 76 km (47 mi) W earthquakes near Ceiba Municipio
Luquillo Municipio, PR 87 km (54 mi) WNW earthquakes near Luquillo Municipio
Naguabo Municipio, PR 87 km (54 mi) W earthquakes near Naguabo Municipio

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

Aftershocks so far

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

  1. 2.5 29 km S of Charlotte Amalie, U.S. Virgin Islands
  2. 2.9 36 km ESE of Isabel Segunda, Puerto Rico
  3. 2.2 29 km NW of Charlotte Amalie, U.S. Virgin Islands
  4. 2.5 12 km N of Charlotte Amalie, U.S. Virgin Islands
  5. 3.5 29 km ENE of Cruz Bay, U.S. Virgin Islands
  6. 2.8 31 km SSW of Charlotte Amalie, U.S. Virgin Islands
  7. 3.1 21 km NNE of Charlotte Amalie, U.S. Virgin Islands
  8. 3.0 22 km S of Charlotte Amalie, U.S. Virgin Islands
  9. 3.4 17 km S of Cruz Bay, U.S. Virgin Islands
  10. 2.9 8 km SE of Culebra, Puerto Rico
  11. 3.0 16 km NE of Cruz Bay, U.S. Virgin Islands
  12. 3.1 36 km NW of Saint Croix, U.S. Virgin Islands
  13. 3.2 7 km WSW of Charlotte Amalie, U.S. Virgin Islands
  14. 3.1 21 km E of Cruz Bay, U.S. Virgin Islands
  15. 2.4 14 km SSE 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.