QuakeIndex

Earthquake · reviewed by a seismologist

M 3.2md

Earthquake near Palmarejo, PR

No earthquake was likely felt in Palmarejo in the 24 hours to 9:26 am AST (13:26 UTC). The last one was M 2.1, 6 km (4 mi) SW, at 11:57 pm AST on 8 November 2026, estimated intensity II (weak) in town. Every earthquake near Palmarejo

This page: a magnitude 3.2 earthquake was recorded 2 km (1 mi) west-southwest of Palmarejo, PR, at 1:09 am AST on 29 October 2021 (05:09 UTC), 13 km deep.

USGS: 2 km WSW of Palmarejo, Puerto Rico

19 km (12 mi) SSE of Mayagüez, PR · 116 km (72 mi) WSW of San Juan, PR

1:09 am AST, Oct 29, 2021 · · 13 km deep · released about 1,800 lb of TNT

Every earthquake near Palmarejo Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lajas Municipio 9 kmCabo Rojo Municipio 10 kmSan Germán Municipio 10 kmHormigueros Municipio 11 kmSabana Grande Municipio 17 kmGuánica Municipio 21 kmMaricao Municipio 23 kmLas Marías Municipio 25 kmYauco Municipio 26 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
1:09 am AST on 29 October 2021 ()
Where
2 km (1 mi) west-southwest of Palmarejo, PR · earthquakes near Palmarejo
Magnitude
M 3.2 (md)
Depth
13 km below the surface
Felt
no reports yet
Nearest
Lajas Municipio, 9 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1764 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 44 km (27 mi) from the epicentre. In Palmarejo, 2 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: San Germán 7 km, intensity III · Puerto Real 11 km, intensity III · Pole Ojea 12 km, intensity III · Mayagüez 19 km, intensity II · Yauco 26 km, intensity II · Guayanilla 32 km, intensity II · Magas Arriba 35 km, intensity II · San Sebastián 35 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1,800 lb 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 6.7 190,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 8,500× the energy of this one
  3. Magna, Utah 2020 M 5.7 6,000× the energy of this one
  4. This earthquake M 3.2 about 1,800 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.9× 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 68,000 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 · 47 km NNW of this epicentre
  2. 5.8 4 km E of Moca, Puerto Rico · 41 km N of this epicentre
  3. 5.2 19 km SW of Stella, Puerto Rico · 34 km WNW of this epicentre
  4. 5.1 21 km SW of Stella, Puerto Rico · 33 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 18.0358, -67.0958. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lajas Municipio, PR 9 km (5 mi) SE earthquakes near Lajas Municipio
Cabo Rojo Municipio, PR 10 km (6 mi) WSW earthquakes near Cabo Rojo Municipio
San Germán Municipio, PR 10 km (6 mi) NE earthquakes near San Germán Municipio
Hormigueros Municipio, PR 11 km (7 mi) N earthquakes near Hormigueros Municipio
Sabana Grande Municipio, PR 17 km (10 mi) ENE earthquakes near Sabana Grande Municipio
Guánica Municipio, PR 21 km (13 mi) ESE 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. 2.3 6 km S of Indios, Puerto Rico
  2. 3.0 9 km SSW of Tallaboa, Puerto Rico
  3. 3.0 4 km SSW of Guánica, Puerto Rico
  4. 2.7 5 km ENE of La Parguera, Puerto Rico
  5. 2.7 6 km WSW of Fuig, Puerto Rico
  6. 2.2 6 km SSE of Indios, Puerto Rico
  7. 2.4 0 km SE of Magas Arriba, Puerto Rico
  8. 3.0 5 km WSW of La Parguera, Puerto Rico
  9. 3.2 6 km WSW of La Parguera, Puerto Rico
  10. 1.8 6 km WSW of La Parguera, Puerto Rico
  11. 2.5 1 km SW of Tallaboa, Puerto Rico
  12. 2.6 1 km NW of Magas Arriba, Puerto Rico
  13. 1.7 1 km SSE of Magas Arriba, Puerto Rico
  14. 2.7 6 km S of Indios, Puerto Rico
  15. 2.5 4 km WSW of Fuig, 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.