QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0md

Earthquake near Guánica, PR

No earthquake was likely felt in Guánica in the 24 hours to 10:49 am AST (14:49 UTC). The last one was M 2.1, 13 km (8 mi) ENE, at 4:39 pm AST on 9 November 2026, estimated intensity II (weak) in town. Every earthquake near Guánica

This page: a magnitude 3.0 earthquake was recorded 7 km (4 mi) west-southwest of Guánica, PR, at 11:53 pm AST on 18 September 2023 (03:53 UTC), 15 km deep.

USGS: 7 km WSW of Guánica, Puerto Rico

37 km (23 mi) W of Ponce, PR · 35 km (22 mi) SSE of Mayagüez, PR

11:53 pm AST, Sep 18, 2023 · · 15 km deep · released about 1,100 lb of TNT

Every earthquake near Guánica Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Guánica Municipio 5 kmLajas Municipio 9 kmSabana Grande Municipio 16 kmGuayanilla Municipio 19 kmYauco Municipio 20 kmSan Germán Municipio 20 kmCabo Rojo Municipio 24 kmMaricao Municipio 26 kmPeñuelas Municipio 27 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
11:53 pm AST on 18 September 2023 ()
Where
7 km (4 mi) west-southwest of Guánica, PR · earthquakes near Guánica
Magnitude
M 3.0 (md)
Depth
15 km below the surface
Felt
no reports yet
Nearest
Guánica Municipio, 5 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1149 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 35 km (22 mi) from the epicentre. In Guánica, 7 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: Yauco 16 km, intensity II · San Germán 18 km, intensity II · Guayanilla 20 km, intensity II · Magas Arriba 23 km, intensity II · Pole Ojea 24 km, intensity II · Tallaboa 27 km, intensity II · Puerto Real 28 km, intensity II · Tallaboa Alta 31 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1,100 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 320,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 14,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 10,000× the energy of this one
  4. This earthquake M 3.0 about 1,100 lb of TNT

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 110,000 times the energy of this one.

Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.

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 17.9387, -66.9655. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Guánica Municipio, PR 5 km (3 mi) ENE earthquakes near Guánica Municipio
Lajas Municipio, PR 9 km (6 mi) WNW earthquakes near Lajas Municipio
Sabana Grande Municipio, PR 16 km (10 mi) N earthquakes near Sabana Grande Municipio
Guayanilla Municipio, PR 19 km (12 mi) ENE earthquakes near Guayanilla Municipio
Yauco Municipio, PR 20 km (12 mi) NE earthquakes near Yauco Municipio
San Germán Municipio, PR 20 km (13 mi) NNW earthquakes near San Germán Municipio

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

Aftershocks so far

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

  1. 2.3 6 km SW of Gu?nica, Puerto Rico
  2. 2.9 3 km WSW of Guánica, Puerto Rico
  3. 2.4 6 km SSE of Maria Antonia, Puerto Rico
  4. 2.4 6 km SW of Guánica, Puerto Rico
  5. 2.5 4 km NNE of Liborio Negron Torres, Puerto Rico
  6. 2.6 6 km WSW of Guánica, Puerto Rico
  7. 2.5 1 km NNE of Guayanilla, Puerto Rico
  8. 2.4 Puerto Rico region
  9. 2.5 Puerto Rico region
  10. 3.3 4 km SW of Guánica, Puerto Rico
  11. 2.9 13 km SSE of Guánica, Puerto Rico
  12. 2.5 5 km SE of Maria Antonia, Puerto Rico
  13. 2.0 5 km SE of Maria Antonia, Puerto Rico
  14. 2.2 8 km SE of Maria Antonia, Puerto Rico
  15. 2.5 10 km SSE of Maria Antonia, 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.