QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

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

Yes. A magnitude 2.1 earthquake was recorded 35 km S of Charlotte Amalie, U.S. Virgin Islands, at 5:05 am AST on 7 August 2017 (09:05 UTC), 32 km deep.

· 32 km deep · released about 38 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Culebra Municipio 48 kmVieques Municipio 49 kmCeiba Municipio 72 kmFajardo Municipio 76 kmNaguabo Municipio 82 kmLuquillo Municipio 86 kmHumacao Municipio 86 kmYabucoa Municipio 93 kmRío Grande Municipio 95 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 2.1 (md)
Depth
32 km below the surface
Felt
no reports yet
Nearest
Culebra Municipio, 48 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3383 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. 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 38 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 390,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 280,000× the energy of this one
  3. Around the size people start to feel M 3.0 25× the energy of this one
  4. This earthquake M 2.1 about 38 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 · 39 km ESE of this epicentre
  2. 5.0 29 km S of Cruz Bay, U.S. Virgin Islands · 24 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 18.0263, -64.9808. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Culebra Municipio, PR 48 km (30 mi) NW earthquakes near Culebra Municipio
Vieques Municipio, PR 49 km (30 mi) WNW earthquakes near Vieques Municipio
Ceiba Municipio, PR 72 km (45 mi) WNW earthquakes near Ceiba Municipio
Fajardo Municipio, PR 76 km (47 mi) WNW earthquakes near Fajardo Municipio
Naguabo Municipio, PR 82 km (51 mi) WNW earthquakes near Naguabo Municipio
Luquillo Municipio, PR 86 km (53 mi) WNW earthquakes near Luquillo Municipio

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

Aftershocks so far

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

  1. 2.3 18 km SSW of Cruz Bay, U.S. Virgin Islands
  2. 1.9 17 km SE of Esperanza, Puerto Rico
  3. 2.9 41 km ESE of Esperanza, Puerto Rico
  4. 2.3 39 km ESE of Esperanza, Puerto Rico
  5. 3.4 2 km ENE of Cruz Bay, U.S. Virgin Islands
  6. 2.5 4 km SSE of Cruz Bay, U.S. Virgin Islands
  7. 2.5 21 km W of Saint Croix, U.S. Virgin Islands
  8. 2.8 26 km S of Charlotte Amalie, U.S. Virgin Islands
  9. 2.5 29 km S of Charlotte Amalie, U.S. Virgin Islands
  10. 2.9 36 km ESE of Isabel Segunda, Puerto Rico
  11. 2.5 12 km N of Charlotte Amalie, U.S. Virgin Islands
  12. 2.8 31 km SSW of Charlotte Amalie, U.S. Virgin Islands
  13. 3.0 22 km S of Charlotte Amalie, U.S. Virgin Islands
  14. 3.4 17 km S of Cruz Bay, U.S. Virgin Islands
  15. 2.9 8 km SE 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.