QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9mwr

4 km SSE of Maria Antonia, Puerto Rico

· 10 km deep · released about 11 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Guánica Municipio 6 kmGuayanilla Municipio 10 kmYauco Municipio 16 kmPeñuelas Municipio 18 kmSabana Grande Municipio 18 kmLajas Municipio 18 kmSan Germán Municipio 26 kmMaricao Municipio 27 kmPonce Municipio 29 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
Magnitude
M 3.9 (mwr)
Depth
10 km below the surface
Felt
19 reports · strongest reported intensity IV
Measured shaking
intensity III (ShakeMap)
Nearest
Guánica Municipio, 6 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2369 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 19 people have reported feeling it to USGS.

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.

Where

Epicentre 17.9408, -66.8707. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Guánica Municipio, PR 6 km (3 mi) E of here earthquakes near Guánica Municipio
Guayanilla Municipio, PR 10 km (7 mi) SW of here earthquakes near Guayanilla Municipio
Yauco Municipio, PR 16 km (10 mi) S of here earthquakes near Yauco Municipio
Peñuelas Municipio, PR 18 km (11 mi) WSW of here earthquakes near Peñuelas Municipio
Sabana Grande Municipio, PR 18 km (11 mi) SSE of here earthquakes near Sabana Grande Municipio
Lajas Municipio, PR 18 km (11 mi) ESE of here earthquakes near Lajas 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 1 km NNW of Indios, Puerto Rico
  2. 2.8 3 km S of Indios, Puerto Rico
  3. 3.1 2 km WSW of Indios, Puerto Rico
  4. 2.5 17 km SSE of Guánica, Puerto Rico
  5. 3.4 16 km SSE of Guánica, Puerto Rico
  6. 2.0 8 km S of Indios, Puerto Rico
  7. 3.1 6 km SW of Guánica, Puerto Rico
  8. 2.1 8 km S of Tallaboa, Puerto Rico
  9. 2.9 2 km SW of Peñuelas, Puerto Rico
  10. 3.5 Puerto Rico region
  11. 1.8 3 km SE of Indios, Puerto Rico
  12. 2.9 3 km SE of Palomas, Puerto Rico
  13. 2.2 5 km SW of Guánica, Puerto Rico
  14. 2.5 26 km S 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.

For this area

The largest earthquake within 50 km in our catalogue was M 6.4 on 2020-01-07 — it released about 5,600 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.