QuakeIndex

Earthquake · reviewed by a seismologist

M 3.2md

Earthquake near San Juan, PR

No earthquake was likely felt in San Juan in the 24 hours to 1:44 am AST (05:44 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 3.2 earthquake was recorded 7 km (4 mi) north of San Juan, PR, at 10:19 pm AST on 9 August 2023 (02:19 UTC), 95 km deep. 1 person has reported feeling it to USGS.

USGS: 6 km N of San Juan, Puerto Rico

14 km (9 mi) NNW of San Juan, PR

10:19 pm AST, Aug 9, 2023 · · 95 km deep · released about 1.1 tons of TNT

Every earthquake near San Juan Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Cataño Municipio 10 kmSan Juan Municipio 12 kmToa Baja Municipio 12 kmDorado Municipio 18 kmLoíza Municipio 19 kmCarolina Municipio 20 kmGuaynabo Municipio 20 kmBayamón Municipio 21 kmToa Alta Municipio 24 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
10:19 pm AST on 9 August 2023 ()
Where
7 km (4 mi) north of San Juan, PR · earthquakes near San Juan
Magnitude
M 3.2 (md)
Depth
95 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Cataño Municipio, 10 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1189 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, 7 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: Cataño, Levittown, Eleanor Roosevelt, Sabana Seca, Bayamón, Ingenio.

How big was it?

This earthquake released about 1.1 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 160,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 7,200× the energy of this one
  3. Magna, Utah 2020 M 5.7 5,100× the energy of this one
  4. This earthquake M 3.2 about 1.1 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.2× 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

The largest earthquake within 50 km since 2016 was M 4.4 on 2018-12-09 — about 57 times the energy of this one.

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

  1. 5.8 12 km N of Garrochales, Puerto Rico · 49 km W of this epicentre
  2. 5.1 3 km W of Aguas Buenas, Puerto Rico · 30 km S of this epicentre
  3. 5.0 3 km N of Brenas, Puerto Rico · 25 km W 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 18.5267, -66.1012. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Cataño Municipio, PR 10 km (6 mi) SSW earthquakes near Cataño Municipio
San Juan Municipio, PR 12 km (8 mi) SSE earthquakes near San Juan Municipio
Toa Baja Municipio, PR 12 km (8 mi) SW earthquakes near Toa Baja Municipio
Dorado Municipio, PR 18 km (11 mi) WSW earthquakes near Dorado Municipio
Loíza Municipio, PR 19 km (12 mi) ESE earthquakes near Loíza Municipio
Carolina Municipio, PR 20 km (12 mi) SE earthquakes near Carolina Municipio

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

Aftershocks so far

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

  1. 2.6 4 km NW of Orocovis, Puerto Rico
  2. 3.0 1 km SSE of Corozal, Puerto Rico
  3. 2.5 3 km ESE of Orocovis, Puerto Rico
  4. 2.9 4 km NNW of Santa Barbara, Puerto Rico
  5. 2.8 5 km NW of Orocovis, Puerto Rico
  6. 2.7 3 km NW of Orocovis, Puerto Rico
  7. 2.9 42 km N of San Juan, Puerto Rico
  8. 2.1 4 km ENE of Bayamon, Puerto Rico
  9. 2.4 4 km ENE of Bayamon, Puerto Rico
  10. 3.1 37 km N of San Juan, Puerto Rico
  11. 3.5 0 km SSW of Bayamón, Puerto Rico
  12. 2.5 7 km ESE of Naranjito, Puerto Rico
  13. 2.3 1 km ENE of Cayey, Puerto Rico
  14. 3.0 Puerto Rico region
  15. 2.5 17 km NNW of Brenas, 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.