QuakeIndex

Earthquake · reviewed by a seismologist

M 3.4md

83 km WSW of Pole Ojea, Puerto Rico

Yes. A magnitude 3.4 earthquake was recorded 83 km WSW of Pole Ojea, Puerto Rico, at 11:16 pm AST on 21 September 2024 (03:16 UTC), 41 km deep.

· 41 km deep · released about 1.8 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mayagüez Municipio 47 kmCabo Rojo Municipio 85 kmLajas Municipio 98 kmHormigueros Municipio 99 kmRincón Municipio 102 kmSan Germán Municipio 104 kmAñasco Municipio 107 kmGuánica Municipio 109 kmAguada Municipio 110 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
41 km below the surface
Felt
no reports yet
Nearest
Mayagüez Municipio, 47 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 781 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 40 km (25 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 1.8 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 92,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 4,100× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,900× the energy of this one
  4. This earthquake M 3.4 about 1.8 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 3.8× 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 4.8 on 2024-08-26 — about 130 times the energy of this one.

Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.

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 17.6575, -67.9023. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mayagüez Municipio, PR 47 km (29 mi) N earthquakes near Mayagüez Municipio
Cabo Rojo Municipio, PR 85 km (53 mi) ENE earthquakes near Cabo Rojo Municipio
Lajas Municipio, PR 98 km (61 mi) ENE earthquakes near Lajas Municipio
Hormigueros Municipio, PR 99 km (61 mi) ENE earthquakes near Hormigueros Municipio
Rincón Municipio, PR 102 km (64 mi) NE earthquakes near Rincón Municipio
San Germán Municipio, PR 104 km (65 mi) ENE earthquakes near San Germán Municipio

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

Aftershocks so far

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

  1. 3.2 61 km SE of Boca de Yuma, Dominican Republic
  2. 3.3 83 km SE of Boca de Yuma, Dominican Republic
  3. 4.7 106 km WSW of Pole Ojea, Puerto Rico
  4. 3.4 65 km SE of Boca de Yuma, Dominican Republic
  5. 3.4 89 km SSE of Boca de Yuma, Dominican Republic
  6. 3.2 75 km SE of Boca de Yuma, Dominican Republic
  7. 3.0 65 km SW of Pole Ojea, Puerto Rico
  8. 3.3 65 km SE of Boca de Yuma, Dominican Republic
  9. 3.3 73 km W of Pole Ojea, Puerto Rico
  10. 3.3 79 km W of Pole Ojea, Puerto Rico
  11. 3.0 64 km WSW of Stella, Puerto Rico
  12. 3.5 71 km SE of Boca de Yuma, Dominican Republic
  13. 3.4 78 km ESE of Boca de Yuma, Dominican Republic
  14. 3.2 72 km SE of Punta Cana, Dominican Republic
  15. 3.1 63 km SE of Boca de Yuma, Dominican Republic

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.