QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1md

Earthquake near Lares, PR

No earthquake was likely felt in Lares in the 24 hours to 2:37 am AST (06:37 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 3.1 earthquake was recorded 9 km (6 mi) south-southeast of Lares, PR, at 4:02 pm AST on 16 July 2020 (20:02 UTC), 12 km deep.

USGS: 9 km SSE of Lares, Puerto Rico

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

4:02 pm AST, Jul 16, 2020 · · 12 km deep · released about 1,200 lb of TNT

10 km30 km60 km120 km N Lares Municipio 7 kmAdjuntas Municipio 9 kmMaricao Municipio 12 kmUtuado Municipio 15 kmLas Marías Municipio 15 kmYauco Municipio 16 kmSan Sebastián Municipio 19 kmSabana Grande Municipio 20 kmHatillo Municipio 24 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
4:02 pm AST on 16 July 2020 ()
Where
9 km (6 mi) south-southeast of Lares, PR · earthquakes near Lares
Magnitude
M 3.1 (md)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Lares Municipio, 7 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2238 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 38 km (24 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 13 km, intensity III · San Sebastián 21 km, intensity II · Yauco 21 km, intensity II · Guayanilla 23 km, intensity II · Tallaboa Alta 24 km, intensity II · Magas Arriba 24 km, intensity II · Jayuya 25 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1,200 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 6.7 280,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 12,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 8,800× the energy of this one
  4. This earthquake M 3.1 about 1,200 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.3× 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 99,000 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 · 47 km WNW of this epicentre
  2. 5.8 12 km N of Garrochales, Puerto Rico · 47 km NE of this epicentre
  3. 5.8 4 km E of Moca, Puerto Rico · 32 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 18.2246, -66.8320. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lares Municipio, PR 7 km (4 mi) NW earthquakes near Lares Municipio
Adjuntas Municipio, PR 9 km (6 mi) ESE earthquakes near Adjuntas Municipio
Maricao Municipio, PR 12 km (8 mi) WSW earthquakes near Maricao Municipio
Utuado Municipio, PR 15 km (9 mi) ENE earthquakes near Utuado Municipio
Las Marías Municipio, PR 15 km (10 mi) W earthquakes near Las Marías 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. 1.5 8 km SSW of Guánica, Puerto Rico
  2. 2.1 9 km SSW of Tallaboa, Puerto Rico
  3. 2.5 7 km WSW of Guánica, Puerto Rico
  4. 2.9 11 km SSE of Maria Antonia, Puerto Rico
  5. 2.7 7 km SSW of Ponce, Puerto Rico
  6. 2.7 7 km ESE of La Parguera, Puerto Rico
  7. 2.7 7 km ESE of La Parguera, Puerto Rico
  8. 3.3 7 km SSE of Maria Antonia, Puerto Rico
  9. 3.2 4 km S of Maria Antonia, Puerto Rico
  10. 2.7 7 km SSW of Guánica, Puerto Rico
  11. 2.8 2 km S of Maria Antonia, Puerto Rico
  12. 2.9 6 km SSW of Guánica, Puerto Rico
  13. 2.5 1 km N of Guayanilla, Puerto Rico
  14. 2.6 4 km WSW of Fuig, Puerto Rico
  15. 2.0 6 km SW of Guánica, 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.