QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4md

Earthquake near Río Lajas, PR

No earthquake was likely felt in Río Lajas in the 24 hours to 6:04 pm AST (22:04 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 2.4 earthquake was recorded 4 km (2 mi) southwest of Río Lajas, PR, at 10:24 am AST on 21 May 2017 (14:24 UTC), 72 km deep.

USGS: 3 km SW of Río Lajas, Puerto Rico

25 km (15 mi) W of San Juan, PR · 14 km (9 mi) W of Bayamón, PR

10:24 am AST, May 21, 2017 · · 72 km deep · released about 120 lb of TNT

Every earthquake near Río Lajas Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Toa Alta Municipio 6 kmVega Alta Municipio 8 kmCorozal Municipio 9 kmNaranjito Municipio 11 kmDorado Municipio 12 kmBayamón Municipio 14 kmVega Baja Municipio 14 kmToa Baja Municipio 14 kmMorovis Municipio 15 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
10:24 am AST on 21 May 2017 ()
Where
4 km (2 mi) southwest of Río Lajas, PR · earthquakes near Río Lajas
Magnitude
M 2.4 (md)
Depth
72 km below the surface
Felt
no reports yet
Nearest
Toa Alta Municipio, 6 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3461 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Río Lajas, 4 km away, the estimate is intensity I (not felt). 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: H. Rivera Colon, Galateo, Corozal, San José, Toa Alta, Vega Alta.

How big was it?

This earthquake released about 120 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 120,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 86,000× the energy of this one
  3. Around the size people start to feel M 3.0 7.7× the energy of this one
  4. This earthquake M 2.4 about 120 lb of TNT

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 3 earthquakes of M5 or more within 50 km:

  1. 5.8 12 km N of Garrochales, Puerto Rico · 35 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 18.3756, -66.2965. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Toa Alta Municipio, PR 6 km (3 mi) ESE earthquakes near Toa Alta Municipio
Vega Alta Municipio, PR 8 km (5 mi) NNW earthquakes near Vega Alta Municipio
Corozal Municipio, PR 9 km (5 mi) SSW earthquakes near Corozal Municipio
Naranjito Municipio, PR 11 km (7 mi) SSE earthquakes near Naranjito Municipio
Dorado Municipio, PR 12 km (7 mi) NNE earthquakes near Dorado Municipio
Bayamón Municipio, PR 14 km (9 mi) ESE earthquakes near Bayamón Municipio

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

Aftershocks so far

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

  1. 2.7 7 km NW of Sumidero, Puerto Rico
  2. 2.8 7 km N of Tierras Nuevas Poniente, Puerto Rico
  3. 2.4 4 km SE of Salinas, Puerto Rico
  4. 3.0 4 km SE of Salinas, Puerto Rico
  5. 2.4 3 km S of Coco, Puerto Rico
  6. 2.7 12 km NNE of Arecibo, Puerto Rico
  7. 1.9 3 km SE of Salinas, Puerto Rico
  8. 3.0 0 km ENE of Río Cañas Abajo, Puerto Rico
  9. 2.6 1 km N of Pueblito del Rio, Puerto Rico
  10. 3.1 24 km NNW of Loíza, Puerto Rico
  11. 2.5 1 km ENE of Salinas, Puerto Rico
  12. 2.8 3 km N of San Juan, Puerto Rico
  13. 3.4 29 km N of Dorado, Puerto Rico
  14. 2.1 0 km SSW of Cayuco, Puerto Rico
  15. 2.1 4 km SSE of Cayey, 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.