QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9md

Earthquake near Aguas Buenas, PR

No earthquake was likely felt in Aguas Buenas in the 24 hours to 1:53 pm AST (17:53 UTC). The last one was M 4.1, 87 km (54 mi) ESE, at 5:44 am AST on 28 October 2026, estimated intensity II (weak) in town; 5 felt reports to USGS. Every earthquake near Aguas Buenas

This page: a magnitude 2.9 earthquake was recorded in Aguas Buenas, PR, at 5:09 pm AST on 29 October 2021 (21:09 UTC), 20 km deep.

USGS: 0 km WNW of Aguas Buenas, Puerto Rico

17 km (10 mi) SSW of San Juan, PR · 8 km (5 mi) WNW of Caguas, PR

5:09 pm AST, Oct 29, 2021 · · 20 km deep · released about 630 lb of TNT

Every earthquake near Aguas Buenas Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Aguas Buenas Municipio 2 kmCaguas Municipio 8 kmGuaynabo Municipio 9 kmCidra Municipio 11 kmBayamón Municipio 12 kmComerío Municipio 12 kmGurabo Municipio 14 kmTrujillo Alto Municipio 14 kmNaranjito Municipio 15 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
5:09 pm AST on 29 October 2021 ()
Where
in Aguas Buenas, PR · earthquakes near Aguas Buenas
Magnitude
M 2.9 (md)
Depth
20 km below the surface
Felt
no reports yet
Nearest
Aguas Buenas Municipio, 2 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1839 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 24 km (15 mi) from the epicentre. 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: Sumidero 5 km, intensity II · Caguas 7 km, intensity II · Guaynabo 11 km, intensity II · Trujillo Alto 15 km, intensity II · Bayamón 16 km, intensity II · Jagual 16 km, intensity II · Cayey 17 km, intensity II · Cataño 20 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 630 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 24,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 17,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.5× the energy of this one
  4. This earthquake M 2.9 about 630 lb of TNT

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 4.6 on 2016-12-05 — about 380 times the energy of this one.

Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:

  1. 5.1 3 km W of Aguas Buenas, Puerto Rico · 3 km W of this epicentre
  2. 5.0 3 km N of Brenas, Puerto Rico · 36 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 18.2595, -66.1103. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Aguas Buenas Municipio, PR 2 km (1 mi) W earthquakes near Aguas Buenas Municipio
Caguas Municipio, PR 8 km (5 mi) SE earthquakes near Caguas Municipio
Guaynabo Municipio, PR 9 km (6 mi) N earthquakes near Guaynabo Municipio
Cidra Municipio, PR 11 km (7 mi) SSW earthquakes near Cidra Municipio
Bayamón Municipio, PR 12 km (7 mi) NNW earthquakes near Bayamón Municipio
Comerío Municipio, PR 12 km (8 mi) WSW earthquakes near Comerío Municipio

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

Aftershocks so far

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

  1. 2.4 1 km SSE of Salinas, Puerto Rico
  2. 3.0 0 km W of Sumidero, Puerto Rico
  3. 2.4 3 km SSE of Pájaros, Puerto Rico
  4. 3.3 1 km ESE of Guaynabo, Puerto Rico
  5. 3.3 1 km WNW of Morovis, Puerto Rico
  6. 2.1 4 km WNW of Coamo, Puerto Rico
  7. 2.9 13 km N of Brenas, Puerto Rico
  8. 2.7 6 km SSE of Salinas, Puerto Rico
  9. 2.6 6 km SSE of Salinas, Puerto Rico
  10. 2.2 6 km SSE of Salinas, Puerto Rico
  11. 2.3 6 km SSE of Salinas, Puerto Rico
  12. 2.2 2 km SSW of Río Cañas Abajo, Puerto Rico
  13. 2.5 4 km SSE of Salinas, Puerto Rico
  14. 2.3 6 km NW of Palomas, Puerto Rico
  15. 2.2 2 km E of G. L. Garcia, 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.