QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1md

Earthquake near San Juan, PR

No earthquake was likely felt in San Juan in the 24 hours to 12:49 pm AST (16:49 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 3.1 earthquake was recorded 45 km (28 mi) northeast of San Juan, PR, at 6:27 am AST on 7 July 2023 (10:27 UTC), 15 km deep.

USGS: 37 km N of Suárez, Puerto Rico

47 km (29 mi) NNE of San Juan, PR · 42 km (26 mi) NNE of Carolina, PR

6:27 am AST, Jul 7, 2023 · · 15 km deep · released about 1,200 lb of TNT

Every earthquake near San Juan Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Loíza Municipio 38 kmRío Grande Municipio 43 kmCarolina Municipio 44 kmLuquillo Municipio 46 kmSan Juan Municipio 46 kmCanóvanas Municipio 49 kmFajardo Municipio 49 kmCataño Municipio 49 kmTrujillo Alto Municipio 51 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
6:27 am AST on 7 July 2023 ()
Where
45 km (28 mi) northeast of San Juan, PR · earthquakes near San Juan
Magnitude
M 3.1 (md)
Depth
15 km below the surface
Felt
no reports yet
Nearest
Loíza Municipio, 38 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1223 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 37 km (23 mi) from the epicentre. In San Juan, 45 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 1,200 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 290,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 13,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 9,100× the energy of this one
  4. This earthquake M 3.1 about 1,200 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.2× more

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 one earthquake of M5 or more within 50 km:

  1. 5.0 73 km NNE of Vieques, Puerto Rico · 43 km NE 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 18.7647, -65.8242. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Loíza Municipio, PR 38 km (23 mi) SSW earthquakes near Loíza Municipio
Río Grande Municipio, PR 43 km (27 mi) S earthquakes near Río Grande Municipio
Carolina Municipio, PR 44 km (27 mi) SSW earthquakes near Carolina Municipio
Luquillo Municipio, PR 46 km (28 mi) SSE earthquakes near Luquillo Municipio
San Juan Municipio, PR 46 km (29 mi) SW earthquakes near San Juan Municipio
Canóvanas Municipio, PR 49 km (30 mi) S earthquakes near Canóvanas Municipio

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

Aftershocks so far

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

  1. 3.2 50 km N of Suárez, Puerto Rico
  2. 3.6 63 km NNE of Vieques, Puerto Rico
  3. 3.1 65 km N of San Juan, Puerto Rico
  4. 3.2 71 km N of San Juan, Puerto Rico
  5. 3.9 52 km N of Suárez, Puerto Rico
  6. 3.5 70 km NNE of Luquillo, Puerto Rico
  7. 3.2 77 km NNE of Vieques, Puerto Rico
  8. 4.2 58 km NNE of Luquillo, Puerto Rico
  9. 2.9 56 km NNE of Luquillo, Puerto Rico
  10. 2.9 4 km NNW of Santa Barbara, Puerto Rico
  11. 2.9 42 km N of San Juan, Puerto Rico
  12. 3.1 37 km N of San Juan, Puerto Rico
  13. 3.2 63 km N of San Juan, Puerto Rico
  14. 3.1 Puerto Rico region
  15. 3.0 53 km N of Loíza, 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.