QuakeIndex

Earthquake · reviewed by a seismologist

M 3.2md

Earthquake near Lares, PR

No earthquake was likely felt in Lares in the 24 hours to 11:00 pm AST (03:00 UTC). The last one was M 3.1, 39 km (24 mi) S, at 3:58 pm AST on 31 October 2026, estimated intensity II (weak) in town. Every earthquake near Lares

This page: a magnitude 3.2 earthquake was recorded 9 km (5 mi) south-southeast of Lares, PR, at 7:58 pm AST on 18 October 2021 (23:58 UTC), 12 km deep. 5 people have reported feeling it to USGS.

USGS: 8 km SSE of Lares, Puerto Rico

34 km (21 mi) NW of Ponce, PR · 28 km (17 mi) SSW of Arecibo, PR

7:58 pm AST, Oct 18, 2021 · · 12 km deep · released about 1.1 tons of TNT

Every earthquake near Lares Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lares Municipio 7 kmAdjuntas Municipio 10 kmMaricao Municipio 12 kmLas Marías Municipio 15 kmUtuado Municipio 15 kmYauco Municipio 16 kmSan Sebastián Municipio 18 kmSabana Grande Municipio 19 kmSan Germán Municipio 25 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
7:58 pm AST on 18 October 2021 ()
Where
9 km (5 mi) south-southeast of Lares, PR · earthquakes near Lares
Magnitude
M 3.2 (md)
Depth
12 km below the surface
Felt
5 reports · strongest reported intensity II
Nearest
Lares Municipio, 7 km NNW
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 47 km (29 mi) from the epicentre. In Lares, 9 km away, the estimate is intensity III (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.

Likely felt in: Lares 9 km, intensity III · Adjuntas 14 km, intensity III · San Sebastián 20 km, intensity II · Yauco 21 km, intensity II · Guayanilla 23 km, intensity II · Magas Arriba 24 km, intensity II · Tallaboa Alta 24 km, intensity II · Jayuya 26 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1.1 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 150,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 6,900× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,900× the energy of this one
  4. This earthquake M 3.2 about 1.1 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.3× 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 55,000 times the energy of this one.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

  1. 6.3 6 km WNW of Aguadilla, Puerto Rico · 46 km WNW of this epicentre
  2. 5.8 12 km N of Garrochales, Puerto Rico · 48 km NE of this epicentre
  3. 5.8 4 km E of Moca, Puerto Rico · 31 km NW 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 18.2240, -66.8398. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lares Municipio, PR 7 km (4 mi) NNW earthquakes near Lares Municipio
Adjuntas Municipio, PR 10 km (6 mi) ESE earthquakes near Adjuntas Municipio
Maricao Municipio, PR 12 km (7 mi) WSW earthquakes near Maricao Municipio
Las Marías Municipio, PR 15 km (9 mi) W earthquakes near Las Marías Municipio
Utuado Municipio, PR 15 km (10 mi) ENE earthquakes near Utuado Municipio
Yauco Municipio, PR 16 km (10 mi) S earthquakes near Yauco Municipio

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

Aftershocks so far

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

  1. 2.6 9 km SSE of Guánica, Puerto Rico
  2. 3.1 8 km SSE of Guánica, Puerto Rico
  3. 3.1 9 km SSE of Guánica, Puerto Rico
  4. 2.9 2 km W of Indios, Puerto Rico
  5. 2.5 2 km SW of Fuig, Puerto Rico
  6. 2.4 1 km NNW of Indios, Puerto Rico
  7. 3.0 12 km S of Guánica, Puerto Rico
  8. 2.6 11 km SSE of Maria Antonia, Puerto Rico
  9. 2.4 3 km W of Indios, Puerto Rico
  10. 2.9 2 km E of Magas Arriba, Puerto Rico
  11. 2.3 14 km SSE of Maria Antonia, Puerto Rico
  12. 3.1 0 km N of Lajas, Puerto Rico
  13. 2.9 6 km WSW of Guánica, Puerto Rico
  14. 1.9 3 km SE of La Parguera, Puerto Rico
  15. 2.9 4 km SE 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.