QuakeIndex

Earthquake · reviewed by a seismologist

M 3.5md

Earthquake near Guánica, PR

Yes: an earthquake was likely felt in Guánica in the last 24 hours. M 2.1, 7 km (4 mi) ENE of Guánica, at 4:14 pm AST on 11 November 2026 (20:14 UTC); the estimated shaking in Guánica was intensity II (weak). Every earthquake near Guánica

This page: a magnitude 3.5 earthquake was recorded 8 km (5 mi) west-southwest of Guánica, PR, at 6:31 pm AST on 4 July 2020 (22:31 UTC), 7.0 km deep. 10 people have reported feeling it to USGS.

USGS: Puerto Rico region

38 km (24 mi) W of Ponce, PR · 32 km (20 mi) SSE of Mayagüez, PR

6:31 pm AST, Jul 4, 2020 · · 7.0 km deep · released about 2.7 tons of TNT

Every earthquake near Guánica Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lajas Municipio 6 kmGuánica Municipio 7 kmSabana Grande Municipio 15 kmSan Germán Municipio 18 kmYauco Municipio 20 kmGuayanilla Municipio 20 kmCabo Rojo Municipio 21 kmHormigueros Municipio 24 kmMaricao 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
6:31 pm AST on 4 July 2020 ()
Where
8 km (5 mi) west-southwest of Guánica, PR · earthquakes near Guánica
Magnitude
M 3.5 (md)
Depth
7.0 km below the surface
Felt
10 reports · strongest reported intensity III
Measured shaking
intensity III (ShakeMap)
Nearest
Lajas Municipio, 6 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2252 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 63 km (39 mi) from the epicentre. In Guánica, 8 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 15 km, intensity III · Yauco 17 km, intensity III · Pole Ojea 21 km, intensity III · Guayanilla 22 km, intensity III · Magas Arriba 24 km, intensity III · Puerto Real 25 km, intensity II · Tallaboa 29 km, intensity II · Tallaboa Alta 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 2.7 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.5 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 63,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 2,800× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,000× the energy of this one
  4. This earthquake M 3.5 about 2.7 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 5.6× 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 in our catalogue was M 6.4 on 2020-01-07 — about 22,000 times the energy of this one.

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 17.9555, -66.9841. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lajas Municipio, PR 6 km (4 mi) WNW earthquakes near Lajas Municipio
Guánica Municipio, PR 7 km (4 mi) E earthquakes near Guánica Municipio
Sabana Grande Municipio, PR 15 km (9 mi) NNE earthquakes near Sabana Grande Municipio
San Germán Municipio, PR 18 km (11 mi) NNW earthquakes near San Germán Municipio
Yauco Municipio, PR 20 km (12 mi) NE earthquakes near Yauco Municipio
Guayanilla Municipio, PR 20 km (13 mi) ENE earthquakes near Guayanilla 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. 2.5 4 km SSW of Guánica, Puerto Rico
  2. 2.9 4 km S of Guánica, Puerto Rico
  3. 2.8 7 km WSW of Fuig, Puerto Rico
  4. 2.7 5 km ENE of La Parguera, Puerto Rico
  5. 2.7 6 km SW of Guánica, Puerto Rico
  6. 3.0 5 km SSW of Guánica, Puerto Rico
  7. 2.3 5 km WNW of Santo Domingo, Puerto Rico
  8. 2.1 14 km SSE of Indios, Puerto Rico
  9. 2.8 4 km S of Guánica, Puerto Rico
  10. 1.9 5 km WSW of Guánica, Puerto Rico
  11. 3.4 4 km SSW of Guánica, Puerto Rico
  12. 2.2 6 km SE of Maria Antonia, Puerto Rico
  13. 1.8 6 km ESE of La Parguera, Puerto Rico
  14. 1.7 5 km WSW of Guánica, Puerto Rico
  15. 2.7 5 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.