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 5:41 pm AST (21:41 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 16 km (10 mi) north-northeast of Brenas, PR, at 7:02 am AST on 10 September 2017 (11:02 UTC), 82 km deep.

USGS: 15 km NNE of Brenas, Puerto Rico

34 km (21 mi) NW of San Juan, PR · 29 km (18 mi) NNW of Bayamón, PR

7:02 am AST, Sep 10, 2017 · · 82 km deep · released about 630 lb of TNT

Every earthquake near Brenas Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Dorado Municipio 15 kmVega Alta Municipio 19 kmVega Baja Municipio 19 kmToa Baja Municipio 20 kmCataño Municipio 24 kmManatí Municipio 27 kmToa Alta Municipio 27 kmBarceloneta Municipio 31 kmBayamón Municipio 32 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
7:02 am AST on 10 September 2017 ()
Where
16 km (10 mi) north-northeast of Brenas, PR · earthquakes near Brenas
Magnitude
M 2.9 (md)
Depth
82 km below the surface
Felt
no reports yet
Nearest
Dorado Municipio, 15 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3256 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, 16 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: Dorado, Sabana, San Antonio, Ceiba, Toa Baja, Monserrate.

How big was it?

This earthquake released about 630 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 24,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 17,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.5× the energy of this one
  4. This earthquake M 2.9 about 630 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 760 times the energy of this one.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

  1. 5.8 12 km N of Garrochales, Puerto Rico · 28 km W of this epicentre
  2. 5.1 3 km W of Aguas Buenas, Puerto Rico · 42 km SSE of this epicentre
  3. 5.0 3 km N of Brenas, Puerto Rico · 12 km SSW 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 18.6030, -66.3050. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Dorado Municipio, PR 15 km (9 mi) SSE earthquakes near Dorado Municipio
Vega Alta Municipio, PR 19 km (12 mi) S earthquakes near Vega Alta Municipio
Vega Baja Municipio, PR 19 km (12 mi) SSW earthquakes near Vega Baja Municipio
Toa Baja Municipio, PR 20 km (12 mi) SE earthquakes near Toa Baja Municipio
Cataño Municipio, PR 24 km (15 mi) SE earthquakes near Cataño Municipio
Manatí Municipio, PR 27 km (16 mi) SW earthquakes near Manatí Municipio

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

Aftershocks so far

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

  1. 2.9 2 km WNW of Vega Baja, Puerto Rico
  2. 2.6 Puerto Rico region
  3. 3.1 8 km NNW of Arecibo, Puerto Rico
  4. 3.1 18 km NNW of Brenas, Puerto Rico
  5. 3.2 40 km N of Arecibo, Puerto Rico
  6. 2.9 53 km NNW of San Juan, Puerto Rico
  7. 2.3 33 km N of Arecibo, Puerto Rico
  8. 2.0 3 km SSE of Carolina, Puerto Rico
  9. 3.2 41 km N of Brenas, Puerto Rico
  10. 2.7 26 km NNW of Brenas, Puerto Rico
  11. 3.2 57 km N of San Juan, Puerto Rico
  12. 2.9 1 km WSW of Cataño, Puerto Rico
  13. 2.6 5 km N of Brenas, Puerto Rico
  14. 1.9 8 km NNE of Animas, Puerto Rico
  15. 2.6 58 km N of Tierras Nuevas Poniente, 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.