QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7md

Earthquake near San Juan, PR

No earthquake was likely felt in San Juan in the 24 hours to 7:41 pm AST (23:41 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 2.7 earthquake was recorded 24 km (15 mi) west-northwest of San Juan, PR, at 10:15 pm AST on 18 March 2018 (02:15 UTC), 39 km deep.

USGS: Puerto Rico region

31 km (19 mi) WNW of San Juan, PR · 25 km (15 mi) NW of Bayamón, PR

10:15 pm AST, Mar 18, 2018 · · 39 km deep · released about 360 lb of TNT

Every earthquake near San Juan Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Dorado Municipio 10 kmVega Alta Municipio 13 kmVega Baja Municipio 13 kmToa Baja Municipio 17 kmCataño Municipio 21 kmManatí Municipio 22 kmToa Alta Municipio 22 kmBarceloneta Municipio 27 kmCorozal 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
10:15 pm AST on 18 March 2018 ()
Where
24 km (15 mi) west-northwest of San Juan, PR · earthquakes near San Juan
Magnitude
M 2.7 (md)
Depth
39 km below the surface
Felt
no reports yet
Nearest
Dorado Municipio, 10 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3160 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 San Juan, 24 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: Brenas, Sabana, San Antonio, Dorado, Ceiba, Monserrate.

How big was it?

This earthquake released about 360 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 42,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 30,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.6× the energy of this one
  4. This earthquake M 2.7 about 360 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 in our catalogue was M 4.8 on 2017-08-18 — about 1,300 times the energy of this one.

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 18.5478, -66.3198. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Dorado Municipio, PR 10 km (6 mi) SE earthquakes near Dorado Municipio
Vega Alta Municipio, PR 13 km (8 mi) S earthquakes near Vega Alta Municipio
Vega Baja Municipio, PR 13 km (8 mi) SW earthquakes near Vega Baja Municipio
Toa Baja Municipio, PR 17 km (10 mi) SE earthquakes near Toa Baja Municipio
Cataño Municipio, PR 21 km (13 mi) ESE earthquakes near Cataño Municipio
Manatí Municipio, PR 22 km (13 mi) WSW earthquakes near Manatí Municipio

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

Aftershocks so far

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

  1. 2.7 22 km NNW of San Juan, Puerto Rico
  2. 3.0 6 km NW of Sabana, Puerto Rico
  3. 2.5 25 km N of Tierras Nuevas Poniente, Puerto Rico
  4. 2.6 17 km N of Tierras Nuevas Poniente, Puerto Rico
  5. 2.5 3 km NW of Barahona, Puerto Rico
  6. 2.4 47 km N of Brenas, Puerto Rico
  7. 2.8 7 km ENE of Arecibo, Puerto Rico
  8. 2.8 2 km NNW of Barceloneta, Puerto Rico
  9. 2.5 1 km WNW of Campanilla, Puerto Rico
  10. 2.2 4 km SW of Comerío, Puerto Rico
  11. 3.1 7 km NNW of Vega Baja, Puerto Rico
  12. 2.8 16 km NNE of Carrizales, Puerto Rico
  13. 3.0 20 km N of Loíza, Puerto Rico
  14. 2.8 37 km N of San Juan, Puerto Rico
  15. 2.6 28 km NNW 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.