QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3md

72 km N of Brenas, Puerto Rico

Yes. A magnitude 3.3 earthquake was recorded 72 km N of Brenas, Puerto Rico, 87 km (54 mi) NNW of San Juan, PR, at 1:34 pm AST on 25 November 2021 (17:34 UTC), 29 km deep.

87 km (54 mi) NNW of San Juan, PR

· 29 km deep · released about 1.5 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Dorado Municipio 73 kmBarceloneta Municipio 74 kmVega Baja Municipio 74 kmManatí Municipio 75 kmVega Alta Municipio 76 kmToa Baja Municipio 77 kmCataño Municipio 80 kmArecibo Municipio 81 kmFlorida Municipio 85 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 3.3 (md)
Depth
29 km below the surface
Felt
no reports yet
Nearest
Dorado Municipio, 73 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1747 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 46 km (29 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 1.5 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 110,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 4,900× the energy of this one
  3. Magna, Utah 2020 M 5.7 3,500× the energy of this one
  4. This earthquake M 3.3 about 1.5 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 3.2× 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 since 2016 was M 4.8 on 2017-08-18 — about 150 times the energy of this one.

Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 61 km N of Hatillo, Puerto Rico · 43 km W of this epicentre
  2. 5.9 78 km N of Arecibo, Puerto Rico · 26 km WNW of this epicentre
  3. 5.7 78 km N of Tierras Nuevas Poniente, Puerto Rico · 16 km WNW of this epicentre
  4. 5.5 64 km N of Tierras Nuevas Poniente, Puerto Rico · 11 km SW of this epicentre
  5. 5.4 106 km N of Brenas, Puerto Rico · 35 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 19.1171, -66.4108. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Dorado Municipio, PR 73 km (45 mi) SSE earthquakes near Dorado Municipio
Barceloneta Municipio, PR 74 km (46 mi) SSW earthquakes near Barceloneta Municipio
Vega Baja Municipio, PR 74 km (46 mi) S earthquakes near Vega Baja Municipio
Manatí Municipio, PR 75 km (47 mi) S earthquakes near Manatí Municipio
Vega Alta Municipio, PR 76 km (47 mi) S earthquakes near Vega Alta Municipio
Toa Baja Municipio, PR 77 km (48 mi) SSE earthquakes near Toa Baja Municipio

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

Aftershocks so far

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

  1. 2.7 29 km N of Garrochales, Puerto Rico
  2. 3.0 67 km N of San Juan, Puerto Rico
  3. 3.1 80 km N of Arecibo, Puerto Rico
  4. 3.7 103 km N of Brenas, Puerto Rico
  5. 3.1 115 km N of Brenas, Puerto Rico
  6. 3.4 45 km N of Brenas, Puerto Rico
  7. 3.1 63 km N of Hatillo, Puerto Rico
  8. 3.3 100 km N of San Juan, Puerto Rico
  9. 3.1 38 km N of Carrizales, Puerto Rico
  10. 3.2 68 km N of Tierras Nuevas Poniente, Puerto Rico
  11. 3.4 72 km N of Tierras Nuevas Poniente, Puerto Rico
  12. 3.3 68 km N of Tierras Nuevas Poniente, Puerto Rico
  13. 3.3 64 km N of Tierras Nuevas Poniente, Puerto Rico
  14. 3.1 Puerto Rico region
  15. 3.1 77 km N of Arecibo, 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.