QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Boquerón, PR

No earthquake was likely felt in Boquerón in the 24 hours to 9:34 pm AST (01:34 UTC). The last one was M 2.1, 6 km (4 mi) ESE, at 11:57 pm AST on 8 November 2026, estimated intensity II (weak) in town. Every earthquake near Boquerón

This page: a magnitude 1.8 earthquake was recorded 3 km (2 mi) northeast of Boquerón, PR, at 11:53 am AST on 4 April 2018 (15:53 UTC), 12 km deep.

USGS: 2 km NE of Boquerón, Puerto Rico

18 km (11 mi) S of Mayagüez, PR · 122 km (76 mi) WSW of San Juan, PR

11:53 am AST, Apr 4, 2018 · · 12 km deep · released about 13 lb of TNT

10 km30 km60 km120 km N Cabo Rojo Municipio 6 kmHormigueros Municipio 11 kmLajas Municipio 14 kmSan Germán Municipio 14 kmSabana Grande Municipio 22 kmGuánica Municipio 26 kmMaricao Municipio 27 kmAñasco Municipio 27 kmLas Marías Municipio 27 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
11:53 am AST on 4 April 2018 ()
Where
3 km (2 mi) northeast of Boquerón, PR · earthquakes near Boquerón
Magnitude
M 1.8 (md)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Cabo Rojo Municipio, 6 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3143 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 5 km (3 mi) from the epicentre. In Boquerón, 3 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.

Likely felt in: Puerto Real 5 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 13 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 840,000× the energy of this one
  3. Around the size people start to feel M 3.0 75× the energy of this one
  4. This earthquake M 1.8 about 13 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

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

  1. 6.3 6 km WNW of Aguadilla, Puerto Rico · 45 km N of this epicentre
  2. 5.8 4 km E of Moca, Puerto Rico · 41 km NNE of this epicentre
  3. 5.2 19 km SW of Stella, Puerto Rico · 28 km NW of this epicentre
  4. 5.1 21 km SW of Stella, Puerto Rico · 27 km WNW 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 18.0431, -67.1495. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Cabo Rojo Municipio, PR 6 km (4 mi) SSW earthquakes near Cabo Rojo Municipio
Hormigueros Municipio, PR 11 km (7 mi) NNE earthquakes near Hormigueros Municipio
Lajas Municipio, PR 14 km (8 mi) ESE earthquakes near Lajas Municipio
San Germán Municipio, PR 14 km (9 mi) ENE earthquakes near San Germán Municipio
Sabana Grande Municipio, PR 22 km (14 mi) ENE earthquakes near Sabana Grande Municipio
Guánica Municipio, PR 26 km (16 mi) ESE earthquakes near Guánica Municipio

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

Aftershocks so far

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

  1. 2.0 8 km WSW of Adjuntas, Puerto Rico
  2. 2.4 1 km N of Puerto Real, Puerto Rico
  3. 2.1 6 km SSW of La Playa, Puerto Rico
  4. 2.2 6 km SSW of La Playa, Puerto Rico
  5. 2.0 2 km NE of Puerto Real, Puerto Rico
  6. 2.1 22 km SSE of Maria Antonia, Puerto Rico
  7. 2.0 11 km NW of Puerto Real, Puerto Rico
  8. 1.8 6 km WSW of Guánica, Puerto Rico
  9. 2.6 24 km WSW of Stella, Puerto Rico
  10. 1.6 0 km SE of La Parguera, Puerto Rico
  11. 2.3 4 km SW of Maricao, Puerto Rico
  12. 2.4 19 km SSE of Maria Antonia, Puerto Rico
  13. 2.7 40 km WSW of Pole Ojea, Puerto Rico
  14. 2.9 5 km WNW of Mayagüez, Puerto Rico
  15. 2.5 4 km WSW of Fuig, 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.