QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9md

54 km N of Brenas, Puerto Rico

Yes. A magnitude 2.9 earthquake was recorded 54 km N of Brenas, Puerto Rico, 70 km (44 mi) NNW of San Juan, PR, at 2:59 pm AST on 19 April 2021 (18:59 UTC), 32 km deep.

70 km (44 mi) NNW of San Juan, PR

· 32 km deep · released about 780 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Dorado Municipio 55 kmVega Baja Municipio 55 kmBarceloneta Municipio 56 kmManatí Municipio 57 kmVega Alta Municipio 58 kmToa Baja Municipio 59 kmCataño Municipio 62 kmArecibo Municipio 65 kmFlorida Municipio 67 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 2.9 (md)
Depth
32 km below the surface
Felt
no reports yet
Nearest
Dorado Municipio, 55 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2032 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 11 km (7 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 780 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 19,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 14,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.2× the energy of this one
  4. This earthquake M 2.9 about 780 lb of TNT

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 620 times the energy of this one.

Before 2016, the USGS record lists 8 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 61 km N of Hatillo, Puerto Rico · 44 km WNW of this epicentre
  2. 5.9 78 km N of Arecibo, Puerto Rico · 36 km NW of this epicentre
  3. 5.8 12 km N of Garrochales, Puerto Rico · 47 km SSW of this epicentre
  4. 5.7 78 km N of Tierras Nuevas Poniente, Puerto Rico · 29 km NW of this epicentre
  5. 5.5 64 km N of Tierras Nuevas Poniente, Puerto Rico · 13 km NW 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 18.9521, -66.3995. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Dorado Municipio, PR 55 km (34 mi) SSE earthquakes near Dorado Municipio
Vega Baja Municipio, PR 55 km (34 mi) S earthquakes near Vega Baja Municipio
Barceloneta Municipio, PR 56 km (35 mi) SSW earthquakes near Barceloneta Municipio
Manatí Municipio, PR 57 km (36 mi) S earthquakes near Manatí Municipio
Vega Alta Municipio, PR 58 km (36 mi) S earthquakes near Vega Alta Municipio
Toa Baja Municipio, PR 59 km (37 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

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

  1. 3.4 65 km N of Brenas, Puerto Rico
  2. 3.3 72 km N of Brenas, Puerto Rico
  3. 3.5 57 km N of San Juan, Puerto Rico
  4. 3.0 76 km N of Tierras Nuevas Poniente, Puerto Rico
  5. 3.0 80 km N of Tierras Nuevas Poniente, Puerto Rico
  6. 3.1 13 km N of Levittown, Puerto Rico
  7. 3.4 80 km N of Tierras Nuevas Poniente, Puerto Rico
  8. 3.5 72 km N of Tierras Nuevas Poniente, Puerto Rico
  9. 3.5 74 km N of Tierras Nuevas Poniente, Puerto Rico
  10. 3.3 75 km N of San Juan, Puerto Rico
  11. 3.0 35 km N of Tierras Nuevas Poniente, Puerto Rico
  12. 3.0 Puerto Rico region
  13. 3.2 74 km N of San Juan, Puerto Rico
  14. 3.5 83 km N of San Juan, Puerto Rico
  15. 3.2 72 km N of San Juan, 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.