QuakeIndex

Earthquake · reviewed by a seismologist

M 5.0ml

Earthquake near Guánica, PR

No earthquake was likely felt in Guánica in the 24 hours to 12:57 pm AST (16:57 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 5.0 earthquake was recorded 11 km (7 mi) south-southeast of Guánica, PR, at 9:06 pm AST on 28 December 2019 (01:06 UTC), 6.0 km deep. 339 people have reported feeling it to USGS.

USGS: 10 km SSE of Guánica, Puerto Rico

28 km (18 mi) WSW of Ponce, PR

9:06 pm AST, Dec 28, 2019 · · 6.0 km deep · released about 480 tons of TNT

Every earthquake near Guánica Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Guánica Municipio 9 kmGuayanilla Municipio 15 kmPeñuelas Municipio 21 kmLajas Municipio 21 kmYauco Municipio 22 kmSabana Grande Municipio 24 kmPonce Municipio 30 kmSan Germán Municipio 31 kmMaricao Municipio 33 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
9:06 pm AST on 28 December 2019 ()
Where
11 km (7 mi) south-southeast of Guánica, PR · earthquakes near Guánica
Magnitude
M 5.0 (ml)
Depth
6.0 km below the surface
Felt
339 reports · strongest reported intensity VI
Measured shaking
intensity V (ShakeMap)
USGS impact alert
green
Nearest
Guánica Municipio, 9 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1331 days ago

This was a moderate earthquake. Shaking at this size can damage poorly built structures close to the epicentre.

At this magnitude and depth, people at rest would likely notice it out to about 193 km (120 mi) from the epicentre. In Guánica, 11 km away, the estimate is intensity V (moderate). 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 17 km, intensity IV · Guayanilla 17 km, intensity IV · Magas Arriba 18 km, intensity IV · Tallaboa 20 km, intensity IV · Tallaboa Alta 25 km, intensity IV · Ponce 29 km, intensity IV · San Germán 29 km, intensity IV · Adjuntas 34 km, intensity IV. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 480 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 6.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 350× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 16× the energy of this one
  3. Magna, Utah 2020 M 5.7 11× the energy of this one
  4. This earthquake M 5.0 about 480 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 1,000× 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 (31 mi) since our catalogue begins in 2016. The previous largest was M 4.7 on 2019-12-28.

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 17.8846, -66.8640. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Guánica Municipio, PR 9 km (6 mi) NW earthquakes near Guánica Municipio
Guayanilla Municipio, PR 15 km (9 mi) NNE earthquakes near Guayanilla Municipio
Peñuelas Municipio, PR 21 km (13 mi) NE earthquakes near Peñuelas Municipio
Lajas Municipio, PR 21 km (13 mi) WNW earthquakes near Lajas Municipio
Yauco Municipio, PR 22 km (14 mi) N earthquakes near Yauco Municipio
Sabana Grande Municipio, PR 24 km (15 mi) NNW 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. 1.8 13 km SSE of Guánica, Puerto Rico
  2. 1.8 9 km S of Indios, Puerto Rico
  3. 1.8 8 km SSE of Guánica, Puerto Rico
  4. 1.8 10 km S of Indios, Puerto Rico
  5. 2.1 7 km SSE of Guánica, Puerto Rico
  6. 2.1 8 km NE of Tallaboa Alta, Puerto Rico
  7. 2.2 17 km SSW of Guánica, Puerto Rico
  8. 1.7 Puerto Rico region
  9. 1.9 11 km S of Indios, Puerto Rico
  10. 2.9 8 km S of Indios, Puerto Rico
  11. 1.9 9 km SE of Maria Antonia, Puerto Rico
  12. 2.0 14 km S of Guánica, Puerto Rico
  13. 1.8 Puerto Rico region
  14. 1.9 9 km SSE of Maria Antonia, Puerto Rico
  15. 2.1 7 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.