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 12:53 pm AST (16:53 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 39 km (24 mi) north of San Juan, PR, at 10:24 pm AST on 27 May 2018 (02:24 UTC), 10 km deep.

USGS: 39 km N of San Juan, Puerto Rico

47 km (29 mi) N of San Juan, PR

10:24 pm AST, May 27, 2018 · · 10 km deep · released about 130 lb of TNT

Every earthquake near San Juan Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Dorado Municipio 40 kmToa Baja Municipio 40 kmCataño Municipio 42 kmSan Juan Municipio 45 kmLoíza Municipio 47 kmVega Alta Municipio 47 kmVega Baja Municipio 48 kmCarolina Municipio 50 kmToa Alta Municipio 52 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
10:24 pm AST on 27 May 2018 ()
Where
39 km (24 mi) north of San Juan, PR · earthquakes near San Juan
Magnitude
M 2.4 (md)
Depth
10 km below the surface
Felt
no reports yet
Nearest
Dorado Municipio, 40 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3090 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 19 km (12 mi) from the epicentre. In San Juan, 39 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.

How big was it?

This earthquake released about 130 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 5.8 120,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 83,000× the energy of this one
  3. Around the size people start to feel M 3.0 7.4× the energy of this one
  4. This earthquake M 2.4 about 130 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 3,700 times the energy of this one.

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

  1. 5.5 64 km N of Tierras Nuevas Poniente, Puerto Rico · 43 km NW of this epicentre
  2. 5.1 66 km N of Brenas, Puerto Rico · 37 km NW of this epicentre
  3. 5.0 3 km N of Brenas, Puerto Rico · 41 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 18.8180, -66.1441. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Dorado Municipio, PR 40 km (25 mi) SSW earthquakes near Dorado Municipio
Toa Baja Municipio, PR 40 km (25 mi) S earthquakes near Toa Baja Municipio
Cataño Municipio, PR 42 km (26 mi) S earthquakes near Cataño Municipio
San Juan Municipio, PR 45 km (28 mi) S earthquakes near San Juan Municipio
Loíza Municipio, PR 47 km (29 mi) SSE earthquakes near Loíza Municipio
Vega Alta Municipio, PR 47 km (29 mi) SSW earthquakes near Vega Alta Municipio

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

Aftershocks so far

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

  1. 2.5 78 km N of San Juan, Puerto Rico
  2. 2.6 67 km N of Tierras Nuevas Poniente, Puerto Rico
  3. 2.5 67 km N of Tierras Nuevas Poniente, Puerto Rico
  4. 2.4 67 km N of Tierras Nuevas Poniente, Puerto Rico
  5. 2.8 68 km N of Tierras Nuevas Poniente, Puerto Rico
  6. 2.9 36 km N of Tierras Nuevas Poniente, Puerto Rico
  7. 2.9 71 km N of Tierras Nuevas Poniente, Puerto Rico
  8. 3.0 54 km N of Tierras Nuevas Poniente, Puerto Rico
  9. 2.9 5 km NNW of Brenas, Puerto Rico
  10. 2.8 Puerto Rico region
  11. 2.7 74 km N of Tierras Nuevas Poniente, Puerto Rico
  12. 2.4 69 km N of Tierras Nuevas Poniente, Puerto Rico
  13. 2.8 74 km N of Tierras Nuevas Poniente, Puerto Rico
  14. 2.7 Puerto Rico region
  15. 2.5 71 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.