QuakeIndex

Earthquake · reviewed by a seismologist

M 3.8md

Earthquake near San Juan, PR

No earthquake was likely felt in San Juan in the 24 hours to 4:28 am AST (08:28 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 3.8 earthquake was recorded 12 km (7 mi) west of San Juan, PR, at 12:39 am AST on 1 May 2022 (04:39 UTC), 97 km deep. 1 person has reported feeling it to USGS.

USGS: Puerto Rico region

18 km (11 mi) WNW of San Juan, PR · 12 km (7 mi) NNW of Bayamón, PR

12:39 am AST, May 1, 2022 · · 97 km deep · released about 7.3 tons of TNT

Every earthquake near San Juan Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Toa Baja Municipio 3 kmDorado Municipio 4 kmCataño Municipio 8 kmToa Alta Municipio 12 kmVega Alta Municipio 13 kmBayamón Municipio 14 kmSan Juan Municipio 17 kmGuaynabo Municipio 18 kmVega Baja Municipio 19 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
12:39 am AST on 1 May 2022 ()
Where
12 km (7 mi) west of San Juan, PR · earthquakes near San Juan
Magnitude
M 3.8 (md)
Depth
97 km below the surface
Felt
1 report · strongest reported intensity II
Measured shaking
intensity II (ShakeMap)
Nearest
Toa Baja Municipio, 3 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1555 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, 12 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: Ingenio, Levittown, Toa Baja, Dorado, Campanilla, Candelaria Arenas.

How big was it?

This earthquake released about 7.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.8 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 23,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 730× the energy of this one
  4. This earthquake M 3.8 about 7.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 15× 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 4.4 on 2018-12-09 — about 8.2 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 18.4685, -66.2201. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Toa Baja Municipio, PR 3 km (2 mi) ESE earthquakes near Toa Baja Municipio
Dorado Municipio, PR 4 km (3 mi) W earthquakes near Dorado Municipio
Cataño Municipio, PR 8 km (5 mi) ESE earthquakes near Cataño Municipio
Toa Alta Municipio, PR 12 km (7 mi) SSW earthquakes near Toa Alta Municipio
Vega Alta Municipio, PR 13 km (8 mi) WSW earthquakes near Vega Alta Municipio
Bayamón Municipio, PR 14 km (9 mi) SSE earthquakes near Bayamón Municipio

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

Aftershocks so far

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

  1. 2.7 4 km ENE of Tierras Nuevas Poniente, Puerto Rico
  2. 3.1 32 km N of San Juan, Puerto Rico
  3. 2.6 4 km E of Palmarejo, Puerto Rico
  4. 3.1 5 km SSE of Pájaros, Puerto Rico
  5. 2.8 7 km NNW of San Juan, Puerto Rico
  6. 2.6 3 km NNW of Coamo, Puerto Rico
  7. 2.9 1 km WNW of Río Lajas, Puerto Rico
  8. 3.0 5 km N of Levittown, Puerto Rico
  9. 2.0 Puerto Rico region
  10. 2.8 20 km N of Tierras Nuevas Poniente, Puerto Rico
  11. 2.7 5 km NW of Orocovis, Puerto Rico
  12. 3.1 1 km NNW of Campanilla, Puerto Rico
  13. 3.1 2 km NW of Cataño, Puerto Rico
  14. 2.8 30 km N of Tierras Nuevas Poniente, Puerto Rico
  15. 2.6 5 km ESE of Naranjito, 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.