QuakeIndex

Earthquake · reviewed by a seismologist

M 4.3ml

Earthquake near La Parguera, PR

No earthquake was likely felt in La Parguera in the 24 hours to 11:34 am AST (15:34 UTC). The last one was M 2.1, 9 km (5 mi) WNW, at 11:57 pm AST on 8 November 2026, estimated intensity II (weak) in town. Every earthquake near La Parguera

This page: a magnitude 4.3 earthquake was recorded 6 km (3 mi) west-southwest of La Parguera, PR, at 12:45 am AST on 18 July 2021 (04:45 UTC), 11 km deep. 30 people have reported feeling it to USGS.

USGS: 5 km WSW of La Parguera, Puerto Rico

28 km (17 mi) S of Mayagüez, PR · 120 km (74 mi) WSW of San Juan, PR

12:45 am AST, Jul 18, 2021 · · 11 km deep · released about 37 tons of TNT

Every earthquake near La Parguera Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lajas Municipio 6 kmCabo Rojo Municipio 10 kmSan Germán Municipio 18 kmGuánica Municipio 18 kmHormigueros Municipio 20 kmSabana Grande Municipio 21 kmYauco Municipio 29 kmMaricao Municipio 30 kmGuayanilla Municipio 32 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
12:45 am AST on 18 July 2021 ()
Where
6 km (3 mi) west-southwest of La Parguera, PR · earthquakes near La Parguera
Magnitude
M 4.3 (ml)
Depth
11 km below the surface
Felt
30 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
USGS impact alert
green
Nearest
Lajas Municipio, 6 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1873 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth, people at rest would likely notice it out to about 117 km (73 mi) from the epicentre. In La Parguera, 6 km away, the estimate is intensity IV (light). 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: Pole Ojea 10 km, intensity IV · San Germán 15 km, intensity IV · Puerto Real 16 km, intensity III · Yauco 27 km, intensity III · Mayagüez 28 km, intensity III · Guayanilla 33 km, intensity III · Magas Arriba 35 km, intensity III · Tallaboa 40 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 37 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 4,600× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 200× the energy of this one
  3. Magna, Utah 2020 M 5.7 140× the energy of this one
  4. This earthquake M 4.3 about 37 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 78× 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 1,600 times the energy of this one.

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

  1. 5.8 4 km E of Moca, Puerto Rico · 50 km N of this epicentre
  2. 5.2 19 km SW of Stella, Puerto Rico · 39 km NW of this epicentre
  3. 5.1 21 km SW of Stella, Puerto Rico · 38 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 17.9553, -67.0951. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lajas Municipio, PR 6 km (4 mi) ENE earthquakes near Lajas Municipio
Cabo Rojo Municipio, PR 10 km (6 mi) WNW earthquakes near Cabo Rojo Municipio
San Germán Municipio, PR 18 km (11 mi) NNE earthquakes near San Germán Municipio
Guánica Municipio, PR 18 km (11 mi) E earthquakes near Guánica Municipio
Hormigueros Municipio, PR 20 km (12 mi) N earthquakes near Hormigueros Municipio
Sabana Grande Municipio, PR 21 km (13 mi) NE earthquakes near Sabana Grande 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. 2.4 5 km WSW of La Parguera, Puerto Rico
  2. 2.8 6 km WSW of La Parguera, Puerto Rico
  3. 3.1 4 km WSW of Fuig, Puerto Rico
  4. 2.5 3 km ESE of La Parguera, Puerto Rico
  5. 2.3 5 km WSW of La Parguera, Puerto Rico
  6. 2.4 12 km SSE of Guánica, Puerto Rico
  7. 2.5 8 km S of Guánica, Puerto Rico
  8. 3.3 2 km S of Magas Arriba, Puerto Rico
  9. 2.2 6 km SSE of Maria Antonia, Puerto Rico
  10. 3.0 7 km SE of Maria Antonia, Puerto Rico
  11. 2.9 2 km SSE of Pole Ojea, Puerto Rico
  12. 2.7 1 km N of Guayanilla, Puerto Rico
  13. 3.1 6 km W of La Parguera, Puerto Rico
  14. 2.2 5 km SW of La Parguera, Puerto Rico
  15. 2.8 3 km S of Pole Ojea, 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.