QuakeIndex

Earthquake · reviewed by a seismologist

M 3.5md

Virgin Islands

Yes. A magnitude 3.5 earthquake was recorded in the Virgin Islands, at 3:20 am AST on 15 July 2023 (07:20 UTC), 27 km deep. 1 person has reported feeling it to USGS.

· 27 km deep · released about 3 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Culebra Municipio 119 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 3.5 (md)
Depth
27 km below the surface
Felt
1 report · strongest reported intensity III
Nearest
Culebra Municipio, 119 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1215 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 59 km (37 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 3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.5 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 57,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 2,500× the energy of this one
  3. Magna, Utah 2020 M 5.7 1,800× the energy of this one
  4. This earthquake M 3.5 about 3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 6.2× 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 in our catalogue was M 5.5 on 2022-05-08 — about 900 times the energy of this one.

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 19.2348, -64.7041. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Culebra Municipio, PR 119 km (74 mi) SSW earthquakes near Culebra Municipio
Fajardo Municipio, PR 133 km (82 mi) SW earthquakes near Fajardo Municipio
Luquillo Municipio, PR 143 km (89 mi) SW earthquakes near Luquillo Municipio
Ceiba Municipio, PR 146 km (91 mi) SW earthquakes near Ceiba Municipio
Río Grande Municipio, PR 150 km (93 mi) SW earthquakes near Río Grande Municipio
Naguabo Municipio, PR 157 km (98 mi) SW earthquakes near Naguabo Municipio

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

Aftershocks so far

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

  1. 3.5 62 km N of Cruz Bay, U.S. Virgin Islands
  2. 3.9 57 km N of Cruz Bay, U.S. Virgin Islands
  3. 3.7 134 km N of Charlotte Amalie, U.S. Virgin Islands
  4. 3.5 96 km NNE of Cruz Bay, U.S. Virgin Islands
  5. 3.7 Virgin Islands
  6. 3.6 92 km NNE of Cruz Bay, U.S. Virgin Islands
  7. 3.8 101 km NNE of Cruz Bay, U.S. Virgin Islands
  8. 3.4 92 km N of Cruz Bay, U.S. Virgin Islands
  9. 3.5 Puerto Rico region
  10. 3.6 60 km NNE of Cruz Bay, U.S. Virgin Islands
  11. 3.6 114 km NNE of Cruz Bay, U.S. Virgin Islands
  12. 3.9 128 km NNE of Cruz Bay, U.S. Virgin Islands
  13. 3.9 138 km N of Charlotte Amalie, U.S. Virgin Islands
  14. 3.7 84 km NNE of Cruz Bay, U.S. Virgin Islands
  15. 3.6 92 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.