QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4md

Earthquake near San Juan, PR

No earthquake was likely felt in San Juan in the 24 hours to 4:30 pm AST (20:30 UTC). The last one was M 4.1, 99 km (62 mi) SE, at 5:44 am AST on 28 October 2026, estimated intensity II (weak) in town; 5 felt reports to USGS. Every earthquake near San Juan

This page: a magnitude 2.4 earthquake was recorded 36 km (23 mi) southwest of San Juan, PR, at 5:33 pm AST on 18 July 2018 (21:33 UTC), 33 km deep.

USGS: 4 km NNE of Orocovis, Puerto Rico

37 km (23 mi) WSW of San Juan, PR · 26 km (16 mi) WSW of Bayamón, PR

5:33 pm AST, Jul 18, 2018 · · 33 km deep · released about 110 lb of TNT

Every earthquake near San Juan Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Morovis Municipio 7 kmCorozal Municipio 7 kmOrocovis Municipio 8 kmBarranquitas Municipio 11 kmNaranjito Municipio 14 kmCiales Municipio 14 kmComerío Municipio 18 kmToa Alta Municipio 18 kmVillalba Municipio 18 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
5:33 pm AST on 18 July 2018 ()
Where
36 km (23 mi) southwest of San Juan, PR · earthquakes near San Juan
Magnitude
M 2.4 (md)
Depth
33 km below the surface
Felt
no reports yet
Nearest
Morovis Municipio, 7 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3038 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 San Juan, 36 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: Morovis, Franquez, Corozal, Barahona, Ciales, Barranquitas.

How big was it?

This earthquake released about 110 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 140,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 99,000× the energy of this one
  3. Around the size people start to feel M 3.0 8.8× the energy of this one
  4. This earthquake M 2.4 about 110 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 3 earthquakes of M5 or more within 50 km:

  1. 5.8 12 km N of Garrochales, Puerto Rico · 38 km NNW of this epicentre
  2. 5.1 3 km W of Aguas Buenas, Puerto Rico · 26 km E of this epicentre
  3. 5.0 3 km N of Brenas, Puerto Rico · 26 km N 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 18.2691, -66.3821. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Morovis Municipio, PR 7 km (4 mi) NW earthquakes near Morovis Municipio
Corozal Municipio, PR 7 km (4 mi) ENE earthquakes near Corozal Municipio
Orocovis Municipio, PR 8 km (5 mi) SW earthquakes near Orocovis Municipio
Barranquitas Municipio, PR 11 km (7 mi) SE earthquakes near Barranquitas Municipio
Naranjito Municipio, PR 14 km (9 mi) E earthquakes near Naranjito Municipio
Ciales Municipio, PR 14 km (9 mi) WNW earthquakes near Ciales Municipio

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

Aftershocks so far

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

  1. 2.0 4 km WSW of Ponce, Puerto Rico
  2. 1.7 2 km NNE of Santo Domingo, Puerto Rico
  3. 2.7 4 km ESE of Florida, Puerto Rico
  4. 2.2 11 km N of Arecibo, Puerto Rico
  5. 1.6 4 km SSW of Adjuntas, Puerto Rico
  6. 2.1 3 km N of Santo Domingo, Puerto Rico
  7. 2.2 1 km SSE of Adjuntas, Puerto Rico
  8. 1.6 3 km SW of Adjuntas, Puerto Rico
  9. 3.0 4 km ESE of Bayamon, Puerto Rico
  10. 1.7 6 km SSE of Adjuntas, Puerto Rico
  11. 2.6 3 km SSE of Guaynabo, Puerto Rico
  12. 1.9 7 km SSE of Ponce, Puerto Rico
  13. 2.1 4 km NNW of Santo Domingo, Puerto Rico
  14. 2.8 3 km NNE of Naranjito, Puerto Rico
  15. 2.0 1 km NE of Sabana Seca, 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.