QuakeIndex

Earthquake · reviewed by a seismologist

M 3.4md

63 km W of Rincón, Puerto Rico

Yes. A magnitude 3.4 earthquake was recorded 63 km W of Rincón, Puerto Rico, at 2:46 am AST on 16 November 2021 (06:46 UTC), 75 km deep.

· 75 km deep · released about 2.1 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mayagüez Municipio 22 kmRincón Municipio 64 kmAguada Municipio 71 kmAñasco Municipio 76 kmCabo Rojo Municipio 77 kmAguadilla Municipio 78 kmHormigueros Municipio 79 kmMoca Municipio 82 kmSan Germán Municipio 88 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
75 km below the surface
Felt
no reports yet
Nearest
Mayagüez Municipio, 22 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1822 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 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 4.5 on 2021-10-14 — about 34 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 6.3 58 km E of Punta Cana, Dominican Republic · 25 km N 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 18.2751, -67.8500. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mayagüez Municipio, PR 22 km (13 mi) S earthquakes near Mayagüez Municipio
Rincón Municipio, PR 64 km (40 mi) E earthquakes near Rincón Municipio
Aguada Municipio, PR 71 km (44 mi) E earthquakes near Aguada Municipio
Añasco Municipio, PR 76 km (47 mi) E earthquakes near Añasco Municipio
Cabo Rojo Municipio, PR 77 km (48 mi) ESE earthquakes near Cabo Rojo Municipio
Aguadilla Municipio, PR 78 km (48 mi) ENE earthquakes near Aguadilla Municipio

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

Aftershocks so far

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

  1. 3.5 18 km WSW of Stella, Puerto Rico
  2. 3.6 21 km SE of Punta Cana, Dominican Republic
  3. 3.1 78 km SE of Boca de Yuma, Dominican Republic
  4. 3.9 28 km SSE of Punta Cana, Dominican Republic
  5. 4.0 56 km SE of Punta Cana, Dominican Republic
  6. 3.5 49 km SSE of Punta Cana, Dominican Republic
  7. 3.0 66 km SE of Punta Cana, Dominican Republic
  8. 3.4 34 km WSW of Stella, Puerto Rico
  9. 3.1 64 km W of Stella, Puerto Rico
  10. 3.4 39 km WSW of Stella, Puerto Rico
  11. 2.2 21 km SW of Stella, Puerto Rico
  12. 2.4 35 km NW of Rincón, Puerto Rico
  13. 1.9 38 km WNW of Rincón, Puerto Rico
  14. 3.4 55 km WSW of Stella, Puerto Rico
  15. 3.3 80 km W of Pole Ojea, 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.