QuakeIndex

Earthquake · reviewed by a seismologist

M 4.2md

Earthquake near Río Lajas, PR

No earthquake was likely felt in Río Lajas in the 24 hours to 10:43 am AST (14:43 UTC). The last one was M 4.8, 88 km (55 mi) SW, at 9:19 am AST on 18 September 2026, estimated intensity III (weak) in town; 86 felt reports to USGS. Every earthquake near Río Lajas

This page: a magnitude 4.2 earthquake was recorded 3 km (2 mi) southwest of Río Lajas, PR, at 10:06 pm AST on 12 April 2026 (02:06 UTC), 115 km deep. 81 people have reported feeling it to USGS.

USGS: 2 km SW of Río Lajas, Puerto Rico

24 km (15 mi) W of San Juan, PR · 13 km (8 mi) W of Bayamón, PR

10:06 pm AST, Apr 12, 2026 · · 115 km deep · released about 26 tons of TNT

Every earthquake near Río Lajas Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Toa Alta Municipio 5 kmVega Alta Municipio 8 kmCorozal Municipio 9 kmNaranjito Municipio 11 kmDorado Municipio 11 kmBayamón Municipio 13 kmToa Baja Municipio 13 kmVega Baja Municipio 14 kmMorovis Municipio 16 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
10:06 pm AST on 12 April 2026 ()
Where
3 km (2 mi) southwest of Río Lajas, PR · earthquakes near Río Lajas
Magnitude
M 4.2 (md)
Depth
115 km below the surface
Felt
81 reports · strongest reported intensity III
Measured shaking
intensity III (ShakeMap)
USGS impact alert
green
Nearest
Toa Alta Municipio, 5 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 140 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Río Lajas, 3 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: Galateo, San José, H. Rivera Colon, Toa Alta, Corozal, Vega Alta.

How big was it?

This earthquake released about 26 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 6,500× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 290× the energy of this one
  3. Magna, Utah 2020 M 5.7 200× the energy of this one
  4. This earthquake M 4.2 about 26 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 55× 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 2.3 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 · 36 km NW of this epicentre
  2. 5.1 3 km W of Aguas Buenas, Puerto Rico · 21 km SE of this epicentre
  3. 5.0 3 km N of Brenas, Puerto Rico · 15 km NNW 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 18.3803, -66.2871. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Toa Alta Municipio, PR 5 km (3 mi) ESE earthquakes near Toa Alta Municipio
Vega Alta Municipio, PR 8 km (5 mi) NW earthquakes near Vega Alta Municipio
Corozal Municipio, PR 9 km (6 mi) SSW earthquakes near Corozal Municipio
Naranjito Municipio, PR 11 km (7 mi) SSE earthquakes near Naranjito Municipio
Dorado Municipio, PR 11 km (7 mi) NNE earthquakes near Dorado Municipio
Bayamón Municipio, PR 13 km (8 mi) ESE earthquakes near Bayamón Municipio

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

Aftershocks so far

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

  1. 2.7 15 km N of San Juan, Puerto Rico
  2. 2.4 4 km NNE of Ponce, Puerto Rico
  3. 2.1 7 km WSW of Naranjito, Puerto Rico
  4. 2.1 5 km NNE of Adjuntas, Puerto Rico
  5. 2.0 6 km S of G. L. Garcia, Puerto Rico
  6. 2.0 2 km ENE of Aguas Buenas, Puerto Rico
  7. 2.0 6 km ENE of Adjuntas, Puerto Rico
  8. 3.2 10 km NNE of Brenas, Puerto Rico
  9. 2.4 4 km SSE of Utuado, Puerto Rico
  10. 2.1 4 km SSE of Utuado, Puerto Rico
  11. 2.4 5 km N of Adjuntas, Puerto Rico
  12. 3.4 8 km NNE of Brenas, Puerto Rico
  13. 1.9 2 km N of Santa Isabel, Puerto Rico
  14. 1.9 1 km SSW of Candelaria Arenas, Puerto Rico
  15. 2.3 0 km SSW of Santa Isabel, 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.