QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1md

Earthquake near Lajas, PR

Yes: an earthquake was likely felt in Lajas in the last 24 hours. M 2.4, 19 km (12 mi) SE of Lajas, at 3:43 pm AST on 11 November 2026 (19:43 UTC); the estimated shaking in Lajas was intensity II (weak). Every earthquake near Lajas

This page: a magnitude 3.1 earthquake was recorded in Lajas, PR, at 7:02 am AST on 27 October 2021 (11:02 UTC), 14 km deep. 1 person has reported feeling it to USGS.

USGS: 0 km N of Lajas, Puerto Rico

19 km (12 mi) SSE of Mayagüez, PR · 112 km (70 mi) WSW of San Juan, PR

7:02 am AST, Oct 27, 2021 · · 14 km deep · released about 1,400 lb of TNT

Every earthquake near Lajas Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Germán Municipio 7 kmLajas Municipio 8 kmHormigueros Municipio 11 kmSabana Grande Municipio 12 kmCabo Rojo Municipio 14 kmGuánica Municipio 18 kmMaricao Municipio 19 kmLas Marías Municipio 21 kmYauco Municipio 22 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
7:02 am AST on 27 October 2021 ()
Where
in Lajas, PR · earthquakes near Lajas
Magnitude
M 3.1 (md)
Depth
14 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
San Germán Municipio, 7 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1557 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 40 km (25 mi) from the epicentre. 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: San Germán 4 km, intensity III · Puerto Real 14 km, intensity III · Pole Ojea 16 km, intensity II · Mayagüez 19 km, intensity II · Yauco 22 km, intensity II · Guayanilla 28 km, intensity II · Magas Arriba 31 km, intensity II · San Sebastián 32 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1,400 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 240,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 11,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 7,700× the energy of this one
  4. This earthquake M 3.1 about 1,400 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.5× 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 6.4 on 2020-01-07 — about 86,000 times the energy of this one.

Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:

  1. 6.3 6 km WNW of Aguadilla, Puerto Rico · 46 km NNW of this epicentre
  2. 5.8 4 km E of Moca, Puerto Rico · 39 km N of this epicentre
  3. 5.2 19 km SW of Stella, Puerto Rico · 36 km WNW of this epicentre
  4. 5.1 21 km SW of Stella, Puerto Rico · 36 km WNW 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 18.0521, -67.0591. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Germán Municipio, PR 7 km (4 mi) NNE earthquakes near San Germán Municipio
Lajas Municipio, PR 8 km (5 mi) SSE earthquakes near Lajas Municipio
Hormigueros Municipio, PR 11 km (7 mi) NNW earthquakes near Hormigueros Municipio
Sabana Grande Municipio, PR 12 km (8 mi) ENE earthquakes near Sabana Grande Municipio
Cabo Rojo Municipio, PR 14 km (9 mi) WSW earthquakes near Cabo Rojo Municipio
Guánica Municipio, PR 18 km (11 mi) SE earthquakes near Guánica Municipio

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

Aftershocks so far

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

  1. 3.1 4 km WSW of Fuig, Puerto Rico
  2. 2.8 5 km WSW of Fuig, Puerto Rico
  3. 3.1 4 km WSW of Fuig, Puerto Rico
  4. 2.4 3 km SSW of Indios, Puerto Rico
  5. 3.2 4 km WSW of Guánica, Puerto Rico
  6. 2.4 7 km WSW of Guánica, Puerto Rico
  7. 3.2 11 km SSW of Guánica, Puerto Rico
  8. 3.0 13 km SSW of Guánica, Puerto Rico
  9. 2.2 1 km NNW of Tallaboa, Puerto Rico
  10. 3.0 4 km SW of Indios, Puerto Rico
  11. 3.3 6 km WSW of Guánica, Puerto Rico
  12. 2.7 5 km WSW of Guánica, Puerto Rico
  13. 2.7 4 km SSE of Tallaboa, Puerto Rico
  14. 2.4 3 km SSW of Indios, Puerto Rico
  15. 2.7 5 km SSE of La Parguera, 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.