QuakeIndex

Earthquake · reviewed by a seismologist

M 3.6md

111 km NNE of Vieques, Puerto Rico

Yes. A magnitude 3.6 earthquake was recorded 111 km NNE of Vieques, Puerto Rico, at 7:18 am AST on 20 December 2024 (11:18 UTC), 90 km deep.

· 90 km deep · released about 4.5 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Fajardo Municipio 109 kmLuquillo Municipio 114 kmCulebra Municipio 114 kmLoíza Municipio 115 kmRío Grande Municipio 116 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 3.6 (md)
Depth
90 km below the surface
Felt
no reports yet
Nearest
Fajardo Municipio, 109 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 622 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 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 4.5 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.7 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 38,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,700× the energy of this one
  3. Magna, Utah 2020 M 5.7 1,200× the energy of this one
  4. This earthquake M 3.6 about 4.5 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 9.4× 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 4.9 on 2018-11-14 — about 75 times the energy of this one.

Before 2016, the USGS record lists 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.0 112 km N of Charlotte Amalie, U.S. Virgin Islands · 49 km E of this epicentre
  2. 5.1 107 km N of Charlotte Amalie, U.S. Virgin Islands · 47 km E of this epicentre
  3. 5.1 122 km NNE of Vieques, Puerto Rico · 12 km NE of this epicentre
  4. 5.1 92 km N of Suárez, Puerto Rico · 35 km WSW of this epicentre
  5. 5.0 109 km N of Charlotte Amalie, U.S. Virgin Islands · 40 km E 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 19.3466, -65.4023. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Fajardo Municipio, PR 109 km (67 mi) S earthquakes near Fajardo Municipio
Luquillo Municipio, PR 114 km (71 mi) SSW earthquakes near Luquillo Municipio
Culebra Municipio, PR 114 km (71 mi) S earthquakes near Culebra Municipio
Loíza Municipio, PR 115 km (72 mi) SSW earthquakes near Loíza Municipio
Río Grande Municipio, PR 116 km (72 mi) SSW earthquakes near Río Grande Municipio
Carolina Municipio, PR 121 km (75 mi) SSW earthquakes near Carolina Municipio

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

Aftershocks so far

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

  1. 3.0 74 km NNW of Charlotte Amalie, U.S. Virgin Islands
  2. 3.3 133 km NNE of Vieques, Puerto Rico
  3. 3.4 130 km NNE of Vieques, Puerto Rico
  4. 3.8 141 km NNE of Vieques, Puerto Rico
  5. 3.7 137 km NNE of Vieques, Puerto Rico
  6. 3.8 121 km NNE of Vieques, Puerto Rico
  7. 4.0 143 km NNE of Vieques, Puerto Rico
  8. 3.7 133 km NNE of Vieques, Puerto Rico
  9. 3.4 106 km NNE of Vieques, Puerto Rico
  10. 3.3 84 km N of Culebra, Puerto Rico
  11. 3.3 85 km N of Culebra, Puerto Rico
  12. 3.3 99 km N of Culebra, Puerto Rico
  13. 3.9 143 km NNE of Vieques, Puerto Rico
  14. 3.7 147 km N of Charlotte Amalie, U.S. Virgin Islands
  15. 3.8 113 km NNE of Vieques, 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.