QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

Earthquake near Brenas, PR

No earthquake was likely felt in Brenas in the 24 hours to 8:06 am AST (12:06 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 2.3 earthquake was recorded 4 km (3 mi) north of Brenas, PR, at 5:49 am AST on 23 June 2018 (09:49 UTC), 113 km deep.

USGS: 4 km N of Brenas, Puerto Rico

31 km (19 mi) WNW of San Juan, PR · 23 km (14 mi) NW of Bayamón, PR

5:49 am AST, Jun 23, 2018 · · 113 km deep · released about 72 lb of TNT

Every earthquake near Brenas Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Vega Alta Municipio 8 kmDorado Municipio 8 kmVega Baja Municipio 9 kmToa Baja Municipio 16 kmManatí Municipio 18 kmToa Alta Municipio 18 kmCataño Municipio 21 kmCorozal Municipio 22 kmMorovis Municipio 23 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
5:49 am AST on 23 June 2018 ()
Where
4 km (3 mi) north of Brenas, PR · earthquakes near Brenas
Magnitude
M 2.3 (md)
Depth
113 km below the surface
Felt
no reports yet
Nearest
Vega Alta Municipio, 8 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2976 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Brenas, 4 km away, the estimate is intensity I (not felt). 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, Ceiba, San Antonio, Monserrate, Dorado, Vega Baja.

How big was it?

This earthquake released about 72 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 210,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 150,000× the energy of this one
  3. Around the size people start to feel M 3.0 13× the energy of this one
  4. This earthquake M 2.3 about 72 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 6,700 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 · 25 km WNW of this epicentre
  2. 5.1 3 km W of Aguas Buenas, Puerto Rico · 34 km SE of this epicentre
  3. 5.0 3 km N of Brenas, Puerto Rico · 1 km WSW 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 18.5048, -66.3341. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Vega Alta Municipio, PR 8 km (5 mi) S earthquakes near Vega Alta Municipio
Dorado Municipio, PR 8 km (5 mi) ESE earthquakes near Dorado Municipio
Vega Baja Municipio, PR 9 km (5 mi) SW earthquakes near Vega Baja Municipio
Toa Baja Municipio, PR 16 km (10 mi) ESE earthquakes near Toa Baja Municipio
Manatí Municipio, PR 18 km (11 mi) WSW earthquakes near Manatí Municipio
Toa Alta Municipio, PR 18 km (11 mi) SSE earthquakes near Toa Alta 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. 2.6 3 km SSE of Guaynabo, Puerto Rico
  2. 2.8 31 km N of Tierras Nuevas Poniente, Puerto Rico
  3. 2.4 33 km NNW of Tierras Nuevas Poniente, Puerto Rico
  4. 2.8 3 km NNE of Naranjito, Puerto Rico
  5. 2.0 1 km NE of Sabana Seca, Puerto Rico
  6. 2.9 5 km SE of Cataño, Puerto Rico
  7. 2.1 7 km E of Naranjito, Puerto Rico
  8. 1.8 3 km NE of Hatillo, Puerto Rico
  9. 2.3 18 km NNE of Arecibo, Puerto Rico
  10. 2.5 33 km N of Tierras Nuevas Poniente, Puerto Rico
  11. 2.3 9 km N of Carrizales, Puerto Rico
  12. 2.4 17 km N of Arecibo, Puerto Rico
  13. 3.2 Puerto Rico region
  14. 2.1 14 km N of Brenas, Puerto Rico
  15. 2.2 29 km NNE 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.