QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near San Juan, PR

No earthquake was likely felt in San Juan in the 24 hours to 1:38 pm AST (17:38 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 2.1 earthquake was recorded 41 km (25 mi) southwest of San Juan, PR, at 1:51 pm AST on 4 September 2024 (17:51 UTC), 39 km deep.

USGS: 4 km NW of Orocovis, Puerto Rico

41 km (26 mi) WSW of San Juan, PR · 31 km (19 mi) WSW of Bayamón, PR

1:51 pm AST, Sep 4, 2024 · · 39 km deep · released about 38 lb of TNT

10 km30 km60 km120 km N Orocovis Municipio 4 kmMorovis Municipio 7 kmCiales Municipio 11 kmCorozal Municipio 11 kmBarranquitas Municipio 13 kmVillalba Municipio 15 kmCoamo Municipio 18 kmNaranjito Municipio 18 kmJayuya Municipio 18 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
1:51 pm AST on 4 September 2024 ()
Where
41 km (25 mi) southwest of San Juan, PR · earthquakes near San Juan
Magnitude
M 2.1 (md)
Depth
39 km below the surface
Felt
no reports yet
Nearest
Orocovis Municipio, 4 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 798 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 San Juan, 41 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: Morovis, Franquez, Ciales, Barahona, Barranquitas, Corozal.

How big was it?

This earthquake released about 38 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 390,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 280,000× the energy of this one
  3. Around the size people start to feel M 3.0 25× the energy of this one
  4. This earthquake M 2.1 about 38 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

The largest earthquake within 50 km since 2016 was M 5.6 on 2020-01-07 — about 200,000 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 · 38 km NNW of this epicentre
  2. 5.1 3 km W of Aguas Buenas, Puerto Rico · 30 km E of this epicentre
  3. 5.0 3 km N of Brenas, Puerto Rico · 29 km NNE 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 18.2538, -66.4198. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orocovis Municipio, PR 4 km (3 mi) SSW earthquakes near Orocovis Municipio
Morovis Municipio, PR 7 km (4 mi) N earthquakes near Morovis Municipio
Ciales Municipio, PR 11 km (7 mi) WNW earthquakes near Ciales Municipio
Corozal Municipio, PR 11 km (7 mi) ENE earthquakes near Corozal Municipio
Barranquitas Municipio, PR 13 km (8 mi) ESE earthquakes near Barranquitas Municipio
Villalba Municipio, PR 15 km (9 mi) SSW earthquakes near Villalba 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. 2.1 1 km NNE of Magas Arriba, Puerto Rico
  2. 3.1 1 km ENE of Magas Arriba, Puerto Rico
  3. 2.4 3 km SSW of Tallaboa, Puerto Rico
  4. 2.4 3 km S of Tallaboa, Puerto Rico
  5. 2.1 7 km SSW of Corozal, Puerto Rico
  6. 2.2 2 km NNE of Guayanilla, Puerto Rico
  7. 2.5 2 km SSE of Guayanilla, Puerto Rico
  8. 2.7 5 km SSE of G. L. Garcia, Puerto Rico
  9. 2.3 0 km ENE of Parcelas La Milagrosa, Puerto Rico
  10. 2.6 3 km S of Tallaboa, Puerto Rico
  11. 3.1 1 km E of Capitanejo, Puerto Rico
  12. 3.1 1 km NE of Magas Arriba, Puerto Rico
  13. 3.3 3 km E of Guayabal, Puerto Rico
  14. 2.1 5 km W of Orocovis, Puerto Rico
  15. 2.6 11 km N of Yauco, 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.