QuakeIndex

Earthquake · reviewed by a seismologist

M 3.4md

113 km NNE of Vieques, Puerto Rico

Yes. A magnitude 3.4 earthquake was recorded 113 km NNE of Vieques, Puerto Rico, at 3:45 am AST on 13 September 2023 (07:45 UTC), 21 km deep.

· 21 km deep · released about 2.1 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Fajardo Municipio 112 kmLuquillo Municipio 116 kmLoíza Municipio 117 kmRío Grande Municipio 118 kmCulebra 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 3.4 (md)
Depth
21 km below the surface
Felt
no reports yet
Nearest
Fajardo Municipio, 112 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1155 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 56 km (35 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 2.1 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.4 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 80,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 3,600× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,500× the energy of this one
  4. This earthquake M 3.4 about 2.1 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 4.4× 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 160 times the energy of this one.

Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:

  1. 5.1 122 km NNE of Vieques, Puerto Rico · 15 km ENE of this epicentre
  2. 5.1 92 km N of Suárez, Puerto Rico · 32 km WSW of this epicentre
  3. 5.0 109 km N of Charlotte Amalie, U.S. Virgin Islands · 46 km E of this epicentre
  4. 5.0 73 km NNE of Vieques, Puerto Rico · 43 km S 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 19.3850, -65.4510. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Fajardo Municipio, PR 112 km (70 mi) S earthquakes near Fajardo Municipio
Luquillo Municipio, PR 116 km (72 mi) SSW earthquakes near Luquillo Municipio
Loíza Municipio, PR 117 km (72 mi) SSW earthquakes near Loíza Municipio
Río Grande Municipio, PR 118 km (73 mi) SSW earthquakes near Río Grande Municipio
Culebra Municipio, PR 119 km (74 mi) S earthquakes near Culebra Municipio
Carolina Municipio, PR 123 km (76 mi) SSW earthquakes near Carolina 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. 3.6 116 km N of Charlotte Amalie, U.S. Virgin Islands
  2. 3.5 70 km NNE of Luquillo, Puerto Rico
  3. 3.4 82 km N of Culebra, Puerto Rico
  4. 3.3 92 km N of Culebra, Puerto Rico
  5. 3.7 92 km NNE of Luquillo, Puerto Rico
  6. 3.2 77 km NNE of Vieques, Puerto Rico
  7. 3.9 148 km NNE of Suárez, Puerto Rico
  8. 3.6 91 km N of Suárez, Puerto Rico
  9. 3.7 132 km N of Suárez, Puerto Rico
  10. 3.7 131 km NNE of San Juan, Puerto Rico
  11. 3.3 89 km N of Suárez, Puerto Rico
  12. 3.9 123 km N of Suárez, Puerto Rico
  13. 3.4 104 km NNE of San Juan, Puerto Rico
  14. 3.8 129 km N of Su?rez, Puerto Rico
  15. 3.1 Puerto Rico region

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.