QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8md

Earthquake near San Juan, PR

No earthquake was likely felt in San Juan in the 24 hours to 12:56 pm AST (16:56 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 2.8 earthquake was recorded 49 km (31 mi) northwest of San Juan, PR, at 5:37 am AST on 28 August 2017 (09:37 UTC), 48 km deep.

USGS: 32 km N of Tierras Nuevas Poniente, Puerto Rico

57 km (36 mi) NW of San Juan, PR · 44 km (27 mi) NE of Arecibo, PR

5:37 am AST, Aug 28, 2017 · · 48 km deep · released about 550 lb of TNT

Every earthquake near San Juan Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Barceloneta Municipio 33 kmVega Baja Municipio 34 kmManatí Municipio 35 kmDorado Municipio 38 kmVega Alta Municipio 38 kmArecibo Municipio 42 kmToa Baja Municipio 44 kmFlorida Municipio 44 kmCataño Municipio 48 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
5:37 am AST on 28 August 2017 ()
Where
49 km (31 mi) northwest of San Juan, PR · earthquakes near San Juan
Magnitude
M 2.8 (md)
Depth
48 km below the surface
Felt
no reports yet
Nearest
Barceloneta Municipio, 33 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3362 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, 49 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 550 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 28,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 19,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.7× the energy of this one
  4. This earthquake M 2.8 about 550 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 870 times the energy of this one.

Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 61 km N of Hatillo, Puerto Rico · 49 km NW of this epicentre
  2. 5.8 12 km N of Garrochales, Puerto Rico · 24 km SSW of this epicentre
  3. 5.7 78 km N of Tierras Nuevas Poniente, Puerto Rico · 47 km NNW of this epicentre
  4. 5.5 64 km N of Tierras Nuevas Poniente, Puerto Rico · 32 km N of this epicentre
  5. 5.1 66 km N of Brenas, Puerto Rico · 37 km NNE 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 18.7546, -66.4635. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Barceloneta Municipio, PR 33 km (21 mi) SSW earthquakes near Barceloneta Municipio
Vega Baja Municipio, PR 34 km (21 mi) SSE earthquakes near Vega Baja Municipio
Manatí Municipio, PR 35 km (21 mi) S earthquakes near Manatí Municipio
Dorado Municipio, PR 38 km (23 mi) SE earthquakes near Dorado Municipio
Vega Alta Municipio, PR 38 km (24 mi) SSE earthquakes near Vega Alta Municipio
Arecibo Municipio, PR 42 km (26 mi) SSW earthquakes near Arecibo Municipio

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

Aftershocks so far

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

  1. 3.0 1 km E of Barceloneta, Puerto Rico
  2. 3.0 11 km N of Camuy, Puerto Rico
  3. 2.5 18 km N of Arecibo, Puerto Rico
  4. 2.9 6 km NNW of Camuy, Puerto Rico
  5. 2.5 2 km WNW of Sabana, Puerto Rico
  6. 2.9 42 km N of Camuy, Puerto Rico
  7. 2.7 69 km N of Tierras Nuevas Poniente, Puerto Rico
  8. 3.3 4 km NE of Brenas, Puerto Rico
  9. 2.4 15 km NNE of Hatillo, Puerto Rico
  10. 3.1 Puerto Rico region
  11. 3.1 Puerto Rico region
  12. 3.3 12 km NNE of Tierras Nuevas Poniente, Puerto Rico
  13. 3.0 68 km NNE of Arecibo, Puerto Rico
  14. 3.1 52 km N of Brenas, Puerto Rico
  15. 2.8 3 km E 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.