QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9Md

Earthquake near San Juan, PR

No earthquake was likely felt in San Juan in the 24 hours to 10:44 am AST (14:44 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 2.9 earthquake was recorded 46 km (28 mi) northwest of San Juan, PR, at 6:37 am AST on 26 March 2017 (10:37 UTC), 20 km deep.

USGS: 32 km NNW of Brenas, Puerto Rico

54 km (33 mi) NW of San Juan, PR · 48 km (30 mi) NE of Arecibo, PR

6:37 am AST, Mar 26, 2017 · · 20 km deep · released about 680 lb of TNT

Every earthquake near San Juan Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Vega Baja Municipio 34 kmDorado Municipio 35 kmBarceloneta Municipio 35 kmManatí Municipio 36 kmVega Alta Municipio 37 kmToa Baja Municipio 41 kmCataño Municipio 45 kmArecibo Municipio 45 kmFlorida Municipio 46 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
6:37 am AST on 26 March 2017 ()
Where
46 km (28 mi) northwest of San Juan, PR · earthquakes near San Juan
Magnitude
M 2.9 (Md)
Depth
20 km below the surface
Felt
no reports yet
Nearest
Vega Baja Municipio, 34 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3517 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, people at rest would likely notice it out to about 25 km (16 mi) from the epicentre. In San Juan, 46 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 680 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 22,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 16,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.4× the energy of this one
  4. This earthquake M 2.9 about 680 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 4.0 on 2017-03-24 — about 45 times the energy of this one.

Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:

  1. 5.8 12 km N of Garrochales, Puerto Rico · 27 km SW of this epicentre
  2. 5.7 78 km N of Tierras Nuevas Poniente, Puerto Rico · 48 km NNW of this epicentre
  3. 5.5 64 km N of Tierras Nuevas Poniente, Puerto Rico · 33 km NNW of this epicentre
  4. 5.1 66 km N of Brenas, Puerto Rico · 35 km N of this epicentre
  5. 5.0 3 km N of Brenas, Puerto Rico · 29 km SSE 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 18.7567, -66.4142. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Vega Baja Municipio, PR 34 km (21 mi) S earthquakes near Vega Baja Municipio
Dorado Municipio, PR 35 km (22 mi) SSE earthquakes near Dorado Municipio
Barceloneta Municipio, PR 35 km (22 mi) SSW earthquakes near Barceloneta Municipio
Manatí Municipio, PR 36 km (22 mi) SSW earthquakes near Manatí Municipio
Vega Alta Municipio, PR 37 km (23 mi) SSE earthquakes near Vega Alta Municipio
Toa Baja Municipio, PR 41 km (25 mi) SE earthquakes near Toa Baja Municipio

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

Aftershocks so far

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

  1. 2.3 5 km NNW of Brenas, Puerto Rico
  2. 1.8 18 km NNE of Arecibo, Puerto Rico
  3. 2.8 29 km N of Garrochales, Puerto Rico
  4. 2.8 55 km N of Brenas, Puerto Rico
  5. 2.8 4 km WNW of San Juan, Puerto Rico
  6. 2.3 45 km N of Brenas, Puerto Rico
  7. 3.0 62 km N of Brenas, Puerto Rico
  8. 3.0 71 km N of San Juan, Puerto Rico
  9. 3.4 2 km NNE of Barahona, Puerto Rico
  10. 2.8 16 km N of Carrizales, Puerto Rico
  11. 2.5 44 km N of Garrochales, Puerto Rico
  12. 3.0 Puerto Rico region
  13. 2.2 Puerto Rico region
  14. 2.8 70 km N of Tierras Nuevas Poniente, Puerto Rico
  15. 2.4 3 km SW of Río Lajas, 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.