QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9md

Earthquake near Brenas, PR

No earthquake was likely felt in Brenas in the 24 hours to 11:23 am AST (15:23 UTC). The last one was M 4.8, 87 km (54 mi) SW, at 9:19 am AST on 18 September 2026, estimated intensity III (weak) in town; 86 felt reports to USGS. Every earthquake near Brenas

This page: a magnitude 2.9 earthquake was recorded 25 km (16 mi) north of Brenas, PR, at 1:42 am AST on 24 August 2017 (05:42 UTC), 50 km deep.

USGS: 24 km N of Brenas, Puerto Rico

42 km (26 mi) NW of San Juan, PR · 38 km (24 mi) NNW of Bayamón, PR

1:42 am AST, Aug 24, 2017 · · 50 km deep · released about 610 lb of TNT

Every earthquake near Brenas Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Dorado Municipio 25 kmVega Baja Municipio 27 kmVega Alta Municipio 28 kmToa Baja Municipio 29 kmManatí Municipio 33 kmCataño Municipio 33 kmBarceloneta Municipio 35 kmToa Alta Municipio 37 kmSan Juan Municipio 40 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
1:42 am AST on 24 August 2017 ()
Where
25 km (16 mi) north of Brenas, PR · earthquakes near Brenas
Magnitude
M 2.9 (md)
Depth
50 km below the surface
Felt
no reports yet
Nearest
Dorado Municipio, 25 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3366 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. In Brenas, 25 km away, the estimate is intensity II (weak). 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.

Earthquakes near other towns within 30 km: Sabana, Dorado, San Antonio, Ceiba, Toa Baja, Vega Baja.

How big was it?

This earthquake released about 610 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 25,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 18,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.6× the energy of this one
  4. This earthquake M 2.9 about 610 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 790 times the energy of this one.

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

  1. 5.8 12 km N of Garrochales, Puerto Rico · 29 km WSW of this epicentre
  2. 5.5 64 km N of Tierras Nuevas Poniente, Puerto Rico · 43 km NNW of this epicentre
  3. 5.1 66 km N of Brenas, Puerto Rico · 42 km N of this epicentre
  4. 5.0 3 km N of Brenas, Puerto Rico · 21 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 18.6911, -66.3211. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Dorado Municipio, PR 25 km (15 mi) SSE earthquakes near Dorado Municipio
Vega Baja Municipio, PR 27 km (17 mi) SSW earthquakes near Vega Baja Municipio
Vega Alta Municipio, PR 28 km (18 mi) S earthquakes near Vega Alta Municipio
Toa Baja Municipio, PR 29 km (18 mi) SSE earthquakes near Toa Baja Municipio
Manatí Municipio, PR 33 km (20 mi) SSW earthquakes near Manatí Municipio
Cataño Municipio, PR 33 km (20 mi) SSE earthquakes near Cataño Municipio

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

Aftershocks so far

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

  1. 2.9 1 km WSW of Cataño, Puerto Rico
  2. 2.6 5 km N of Brenas, Puerto Rico
  3. 2.7 72 km N of Tierras Nuevas Poniente, Puerto Rico
  4. 1.9 8 km NNE of Animas, Puerto Rico
  5. 3.0 59 km N of Arecibo, Puerto Rico
  6. 2.6 58 km N of Tierras Nuevas Poniente, Puerto Rico
  7. 2.7 10 km NNW of Tierras Nuevas Poniente, Puerto Rico
  8. 3.0 1 km E of Barceloneta, Puerto Rico
  9. 2.5 18 km N of Arecibo, Puerto Rico
  10. 2.5 2 km WNW of Sabana, Puerto Rico
  11. 2.7 69 km N of Tierras Nuevas Poniente, Puerto Rico
  12. 3.3 4 km NE of Brenas, Puerto Rico
  13. 3.1 Puerto Rico region
  14. 3.3 12 km NNE of Tierras Nuevas Poniente, Puerto Rico
  15. 3.1 52 km N of Brenas, 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.