QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1md

Earthquake near Yauco, PR

No earthquake was likely felt in Yauco in the 24 hours to 10:21 am AST (14:21 UTC). The last one was M 2.1, 6 km (4 mi) ESE, at 4:39 pm AST on 9 November 2026, estimated intensity II (weak) in town. Every earthquake near Yauco

This page: a magnitude 3.1 earthquake was recorded 4 km (3 mi) northeast of Yauco, PR, at 5:41 pm AST on 29 July 2021 (21:41 UTC), 17 km deep. 1 person has reported feeling it to USGS.

USGS: 4 km NE of Yauco, Puerto Rico

22 km (13 mi) WNW of Ponce, PR

5:41 pm AST, Jul 29, 2021 · · 17 km deep · released about 1,200 lb of TNT

Every earthquake near Yauco Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Yauco Municipio 5 kmGuayanilla Municipio 6 kmPeñuelas Municipio 10 kmSabana Grande Municipio 14 kmAdjuntas Municipio 15 kmGuánica Municipio 16 kmMaricao Municipio 18 kmPonce Municipio 23 kmSan Germán Municipio 24 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
5:41 pm AST on 29 July 2021 ()
Where
4 km (3 mi) northeast of Yauco, PR · earthquakes near Yauco
Magnitude
M 3.1 (md)
Depth
17 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Yauco Municipio, 5 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1555 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 36 km (22 mi) from the epicentre. In Yauco, 4 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 4 km, intensity III · Guayanilla 5 km, intensity III · Magas Arriba 7 km, intensity III · Tallaboa Alta 13 km, intensity II · Tallaboa 13 km, intensity II · Adjuntas 16 km, intensity II · Ponce 21 km, intensity II · San Germán 24 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1,200 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 6.7 290,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 13,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 9,100× the energy of this one
  4. This earthquake M 3.1 about 1,200 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.2× 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 100,000 times the energy of this one.

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

  1. 5.8 4 km E of Moca, Puerto Rico · 46 km NW 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 18.0568, -66.8191. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Yauco Municipio, PR 5 km (3 mi) NW earthquakes near Yauco Municipio
Guayanilla Municipio, PR 6 km (4 mi) SSE earthquakes near Guayanilla Municipio
Peñuelas Municipio, PR 10 km (6 mi) ESE earthquakes near Peñuelas Municipio
Sabana Grande Municipio, PR 14 km (9 mi) WNW earthquakes near Sabana Grande Municipio
Adjuntas Municipio, PR 15 km (10 mi) NNE earthquakes near Adjuntas Municipio
Guánica Municipio, PR 16 km (10 mi) SW earthquakes near Guánica Municipio

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

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

  1. 2.6 4 km SSW of Guánica, Puerto Rico
  2. 2.6 6 km E of La Parguera, Puerto Rico
  3. 2.4 6 km S of Indios, Puerto Rico
  4. 2.3 2 km NNW of Indios, Puerto Rico
  5. 1.7 6 km SSE of Tallaboa, Puerto Rico
  6. 2.3 Puerto Rico region
  7. 3.0 9 km SSE of Maria Antonia, Puerto Rico
  8. 2.7 0 km N of Guánica, Puerto Rico
  9. 3.0 4 km SSE of La Parguera, Puerto Rico
  10. 2.9 3 km W of Fuig, Puerto Rico
  11. 2.3 14 km S of Guánica, Puerto Rico
  12. 2.4 4 km WSW of Fuig, Puerto Rico
  13. 2.6 Puerto Rico region
  14. 2.9 12 km SSE of Maria Antonia, Puerto Rico
  15. 2.4 6 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.