QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

36 km NNE of Cruz Bay, U.S. Virgin Islands

Yes. A magnitude 1.8 earthquake was recorded 36 km NNE of Cruz Bay, U.S. Virgin Islands, at 8:02 am AST on 22 August 2017 (12:02 UTC), 56 km deep.

· 56 km deep · released about 14 lb of TNT

10 km30 km60 km120 km N Culebra Municipio 77 kmVieques Municipio 100 kmFajardo Municipio 102 kmCeiba Municipio 110 kmLuquillo Municipio 115 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 1.8 (md)
Depth
56 km below the surface
Felt
no reports yet
Nearest
Culebra Municipio, 77 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3368 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 14 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 760,000× the energy of this one
  3. Around the size people start to feel M 3.0 68× the energy of this one
  4. This earthquake M 1.8 about 14 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 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.9 68 km N of Cruz Bay, U.S. Virgin Islands · 35 km N of this epicentre
  2. 5.9 65 km NNE of Cruz Bay, U.S. Virgin Islands · 30 km NNE of this epicentre
  3. 5.7 80 km NNE of Cruz Bay, U.S. Virgin Islands · 44 km N of this epicentre
  4. 5.3 78 km NNE of Cruz Bay, U.S. Virgin Islands · 43 km N of this epicentre
  5. 5.2 36 km NNE of Cruz Bay, U.S. Virgin Islands · 5 km WNW 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 18.6341, -64.6558. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Culebra Municipio, PR 77 km (48 mi) WSW earthquakes near Culebra Municipio
Vieques Municipio, PR 100 km (62 mi) SW earthquakes near Vieques Municipio
Fajardo Municipio, PR 102 km (63 mi) WSW earthquakes near Fajardo Municipio
Ceiba Municipio, PR 110 km (69 mi) WSW earthquakes near Ceiba Municipio
Luquillo Municipio, PR 115 km (71 mi) WSW earthquakes near Luquillo Municipio
Naguabo Municipio, PR 123 km (77 mi) WSW earthquakes near Naguabo Municipio

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

Aftershocks so far

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

  1. 3.4 52 km N of Charlotte Amalie, U.S. Virgin Islands
  2. 3.3 34 km NW of Charlotte Amalie, U.S. Virgin Islands
  3. 2.9 59 km N of Charlotte Amalie, U.S. Virgin Islands
  4. 3.4 51 km N of Charlotte Amalie, U.S. Virgin Islands
  5. 3.4 79 km NNE of Cruz Bay, U.S. Virgin Islands
  6. 3.4 56 km N of Charlotte Amalie, U.S. Virgin Islands
  7. 3.7 50 km NNW of Charlotte Amalie, U.S. Virgin Islands
  8. 3.1 58 km NNE of Cruz Bay, U.S. Virgin Islands
  9. 3.8 55 km N of Cruz Bay, U.S. Virgin Islands
  10. 2.2 4 km SE of Charlotte Amalie, U.S. Virgin Islands
  11. 3.6 81 km NNE of Cruz Bay, U.S. Virgin Islands
  12. 3.4 47 km N of Charlotte Amalie, U.S. Virgin Islands
  13. 3.6 53 km NE of Cruz Bay, U.S. Virgin Islands
  14. 3.4 63 km NNE of Cruz Bay, U.S. Virgin Islands
  15. 3.6 75 km N 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.