QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1md

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 3.1 earthquake was recorded 16 km (10 mi) south-southeast of Maria Antonia, PR, at 12:13 pm AST on 30 September 2021 (16:13 UTC), 10 km deep.

USGS: 15 km SSE of Maria Antonia, Puerto Rico

28 km (18 mi) SW of Ponce, PR

12:13 pm AST, Sep 30, 2021 · · 10 km deep · released about 1,400 lb of TNT

Every earthquake near Maria Antonia Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Guánica Municipio 15 kmGuayanilla Municipio 18 kmPeñuelas Municipio 23 kmLajas Municipio 26 kmYauco Municipio 27 kmSabana Grande Municipio 29 kmPonce Municipio 30 kmSan Germán Municipio 36 kmMaricao Municipio 38 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
12:13 pm AST on 30 September 2021 ()
Where
16 km (10 mi) south-southeast of Maria Antonia, PR · earthquakes near Maria Antonia
Magnitude
M 3.1 (md)
Depth
10 km below the surface
Felt
no reports yet
Nearest
Guánica Municipio, 15 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1803 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 41 km (25 mi) from the epicentre. In Maria Antonia, 16 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: Guayanilla 20 km, intensity II · Magas Arriba 20 km, intensity II · Tallaboa 21 km, intensity II · Yauco 21 km, intensity II · Tallaboa Alta 27 km, intensity II · Ponce 29 km, intensity II · San Germán 34 km, intensity II · Adjuntas 37 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1,400 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 240,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 11,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 7,700× the energy of this one
  4. This earthquake M 3.1 about 1,400 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.5× 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 86,000 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 17.8458, -66.8375. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Guánica Municipio, PR 15 km (9 mi) NW earthquakes near Guánica Municipio
Guayanilla Municipio, PR 18 km (11 mi) NNE earthquakes near Guayanilla Municipio
Peñuelas Municipio, PR 23 km (14 mi) NNE earthquakes near Peñuelas Municipio
Lajas Municipio, PR 26 km (16 mi) NW earthquakes near Lajas Municipio
Yauco Municipio, PR 27 km (17 mi) N earthquakes near Yauco Municipio
Sabana Grande Municipio, PR 29 km (18 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

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

  1. 2.9 1 km NNW of Indios, Puerto Rico
  2. 2.9 2 km SE of Guánica, Puerto Rico
  3. 2.4 5 km SE of Maria Antonia, Puerto Rico
  4. 2.9 8 km SSE of Tallaboa, Puerto Rico
  5. 2.8 5 km SE of Maria Antonia, Puerto Rico
  6. 2.3 4 km SE of Indios, Puerto Rico
  7. 2.4 1 km S of Palomas, Puerto Rico
  8. 2.2 3 km SSE of Guánica, Puerto Rico
  9. 3.0 1 km WSW of Indios, Puerto Rico
  10. 2.9 Puerto Rico region
  11. 2.6 7 km S of Indios, Puerto Rico
  12. 3.0 6 km WSW of Fuig, Puerto Rico
  13. 2.5 17 km SSE of Guánica, Puerto Rico
  14. 2.4 4 km SSW of Indios, Puerto Rico
  15. 2.9 1 km SSW of Indios, 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.