QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9ml

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 3.9 earthquake was recorded 8 km (5 mi) west-southwest of Guánica, PR, at 3:49 pm AST on 15 January 2020 (19:49 UTC), 4.0 km deep. 2 people have reported feeling it to USGS.

USGS: 8 km WSW of Guánica, Puerto Rico

38 km (24 mi) WSW of Ponce, PR · 35 km (22 mi) SSE of Mayagüez, PR

3:49 pm AST, Jan 15, 2020 · · 4.0 km deep · released about 11 tons of TNT

Every earthquake near Guánica Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Guánica Municipio 6 kmLajas Municipio 9 kmSabana Grande Municipio 17 kmGuayanilla Municipio 20 kmSan Germán Municipio 21 kmYauco Municipio 21 kmCabo Rojo Municipio 23 kmHormigueros Municipio 27 kmMaricao 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
3:49 pm AST on 15 January 2020 ()
Where
8 km (5 mi) west-southwest of Guánica, PR · earthquakes near Guánica
Magnitude
M 3.9 (ml)
Depth
4.0 km below the surface
Felt
2 reports · strongest reported intensity II
Nearest
Guánica Municipio, 6 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2408 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 89 km (55 mi) from the epicentre. In Guánica, 8 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: Yauco 18 km, intensity III · San Germán 18 km, intensity III · Guayanilla 22 km, intensity III · Pole Ojea 23 km, intensity III · Magas Arriba 24 km, intensity III · Puerto Real 28 km, intensity III · Tallaboa 28 km, intensity III · Tallaboa Alta 32 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 11 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.9 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 16,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 710× the energy of this one
  3. Magna, Utah 2020 M 5.7 500× the energy of this one
  4. This earthquake M 3.9 about 11 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 22× 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 5,600 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.1 21 km SW of Stella, Puerto Rico · 50 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 17.9310, -66.9741. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Guánica Municipio, PR 6 km (4 mi) ENE earthquakes near Guánica Municipio
Lajas Municipio, PR 9 km (5 mi) NW earthquakes near Lajas Municipio
Sabana Grande Municipio, PR 17 km (11 mi) N earthquakes near Sabana Grande Municipio
Guayanilla Municipio, PR 20 km (13 mi) ENE earthquakes near Guayanilla Municipio
San Germán Municipio, PR 21 km (13 mi) NNW earthquakes near San Germán Municipio
Yauco Municipio, PR 21 km (13 mi) NE earthquakes near Yauco 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. 3.1 4 km SW of Guánica, Puerto Rico
  2. 2.5 7 km ESE of La Parguera, Puerto Rico
  3. 3.1 4 km S of Indios, Puerto Rico
  4. 2.3 8 km S of Indios, Puerto Rico
  5. 3.4 10 km SSE of Guánica, Puerto Rico
  6. 3.0 6 km SE of La Parguera, Puerto Rico
  7. 2.3 10 km SSE of Maria Antonia, Puerto Rico
  8. 2.7 8 km S of Indios, Puerto Rico
  9. 2.9 7 km SSW of Indios, Puerto Rico
  10. 1.9 5 km WSW of Guánica, Puerto Rico
  11. 2.5 7 km SE of Maria Antonia, Puerto Rico
  12. 2.5 6 km WSW of Guánica, Puerto Rico
  13. 2.7 5 km SSE of Guánica, Puerto Rico
  14. 2.7 4 km SW of Guánica, Puerto Rico
  15. 2.6 6 km SW of Guánica, 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.