QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9ml

Earthquake near Maria Antonia, PR

Yes: an earthquake was likely felt in Maria Antonia in the last 24 hours. M 2.1, 5 km (3 mi) ENE of Maria Antonia, at 4:14 pm AST on 11 November 2026 (20:14 UTC); the estimated shaking in Maria Antonia was intensity II (weak). Every earthquake near Maria Antonia

This page: a magnitude 3.9 earthquake was recorded 10 km (6 mi) south-southeast of Maria Antonia, PR, at 12:44 am AST on 23 July 2020 (04:44 UTC), 12 km deep. 49 people have reported feeling it to USGS.

USGS: 9 km SSE of Maria Antonia, Puerto Rico

28 km (17 mi) WSW of Ponce, PR

12:44 am AST, Jul 23, 2020 · · 12 km deep · released about 10 tons of TNT

Every earthquake near Maria Antonia Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Guánica Municipio 9 kmGuayanilla Municipio 14 kmPeñuelas Municipio 20 kmYauco Municipio 21 kmLajas Municipio 21 kmSabana Grande Municipio 23 kmPonce Municipio 29 kmSan Germán Municipio 30 kmMaricao Municipio 32 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
12:44 am AST on 23 July 2020 ()
Where
10 km (6 mi) south-southeast of Maria Antonia, PR · earthquakes near Maria Antonia
Magnitude
M 3.9 (ml)
Depth
12 km below the surface
Felt
49 reports · strongest reported intensity VI
Measured shaking
intensity III (ShakeMap)
Nearest
Guánica Municipio, 9 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2230 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 88 km (55 mi) from the epicentre. In Maria Antonia, 10 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 15 km, intensity III · Guayanilla 15 km, intensity III · Magas Arriba 17 km, intensity III · Tallaboa 19 km, intensity III · Tallaboa Alta 24 km, intensity III · Ponce 28 km, intensity III · San Germán 28 km, intensity III · Adjuntas 33 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 10 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 5.8 730× the energy of this one
  3. Magna, Utah 2020 M 5.7 520× the energy of this one
  4. This earthquake M 3.9 about 10 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 5,800 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 17.8961, -66.8605. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Guánica Municipio, PR 9 km (5 mi) NW earthquakes near Guánica Municipio
Guayanilla Municipio, PR 14 km (9 mi) NNE earthquakes near Guayanilla Municipio
Peñuelas Municipio, PR 20 km (13 mi) NE earthquakes near Peñuelas Municipio
Yauco Municipio, PR 21 km (13 mi) N earthquakes near Yauco Municipio
Lajas Municipio, PR 21 km (13 mi) WNW earthquakes near Lajas Municipio
Sabana Grande Municipio, PR 23 km (14 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. 2.7 5 km WSW of Guánica, Puerto Rico
  2. 2.6 11 km S of Guánica, Puerto Rico
  3. 2.5 2 km S of Maria Antonia, Puerto Rico
  4. 2.5 5 km SSE of Guánica, Puerto Rico
  5. 2.6 4 km SE of Lajas, Puerto Rico
  6. 2.0 7 km S of Indios, Puerto Rico
  7. 2.5 14 km S of Guánica, Puerto Rico
  8. 2.2 6 km SSE of Guánica, Puerto Rico
  9. 3.2 5 km SE of La Parguera, Puerto Rico
  10. 1.8 6 km WSW of Guánica, Puerto Rico
  11. 3.0 2 km SE of La Parguera, Puerto Rico
  12. 2.0 6 km WSW of Fuig, Puerto Rico
  13. 2.9 6 km SE of La Parguera, Puerto Rico
  14. 2.5 11 km SSE of Maria Antonia, Puerto Rico
  15. 2.4 1 km SSE of Magas Arriba, 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.