QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3md

Earthquake near San Juan, PR

No earthquake was likely felt in San Juan in the 24 hours to 10:10 am AST (14:10 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 3.3 earthquake was recorded 45 km (28 mi) northwest of San Juan, PR, at 4:14 am AST on 15 July 2023 (08:14 UTC), 37 km deep. 2 people have reported feeling it to USGS.

USGS: Puerto Rico region

52 km (32 mi) NW of San Juan, PR · 40 km (25 mi) NE of Arecibo, PR

4:14 am AST, Jul 15, 2023 · · 37 km deep · released about 1.3 tons of TNT

Every earthquake near San Juan Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Vega Baja Municipio 27 kmBarceloneta Municipio 27 kmManatí Municipio 28 kmVega Alta Municipio 31 kmDorado Municipio 32 kmArecibo Municipio 37 kmFlorida Municipio 38 kmToa Baja Municipio 38 kmMorovis Municipio 42 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
4:14 am AST on 15 July 2023 ()
Where
45 km (28 mi) northwest of San Juan, PR · earthquakes near San Juan
Magnitude
M 3.3 (md)
Depth
37 km below the surface
Felt
2 reports · strongest reported intensity II
Nearest
Vega Baja Municipio, 27 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1215 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.

Likely felt in: Barceloneta 28 km, intensity II · Vega Baja 28 km, intensity II · San Antonio 31 km, intensity II · Dorado 33 km, intensity II · Arecibo 37 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 130,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 5,600× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,000× the energy of this one
  4. This earthquake M 3.3 about 1.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.8× 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 in our catalogue was M 4.8 on 2017-08-18 — about 180 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 18.6925, -66.4543. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Vega Baja Municipio, PR 27 km (17 mi) SSE earthquakes near Vega Baja Municipio
Barceloneta Municipio, PR 27 km (17 mi) SSW earthquakes near Barceloneta Municipio
Manatí Municipio, PR 28 km (17 mi) S earthquakes near Manatí Municipio
Vega Alta Municipio, PR 31 km (19 mi) SSE earthquakes near Vega Alta Municipio
Dorado Municipio, PR 32 km (20 mi) SE earthquakes near Dorado Municipio
Arecibo Municipio, PR 37 km (23 mi) SW earthquakes near Arecibo Municipio

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

Aftershocks so far

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

  1. 2.7 14 km NE of Arecibo, Puerto Rico
  2. 3.0 Puerto Rico region
  3. 3.3 49 km N of Tierras Nuevas Poniente, Puerto Rico
  4. 3.0 67 km N of Brenas, Puerto Rico
  5. 2.6 4 km NNE of Carrizales, Puerto Rico
  6. 2.5 17 km NNW of Brenas, Puerto Rico
  7. 3.5 3 km WSW of Manatí, Puerto Rico
  8. 2.9 35 km N of Carrizales, Puerto Rico
  9. 2.8 20 km N of Carrizales, Puerto Rico
  10. 2.6 16 km NNW of Camuy, Puerto Rico
  11. 2.5 39 km N of Tierras Nuevas Poniente, Puerto Rico
  12. 2.7 11 km N of Arecibo, Puerto Rico
  13. 3.3 Puerto Rico region
  14. 3.0 Puerto Rico region
  15. 3.1 52 km N 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.