QuakeIndex

Earthquake · reviewed by a seismologist

M 3.4md

Earthquake near Central Aguirre, PR

No earthquake was likely felt in Central Aguirre in the 24 hours to 10:50 am AST (14:50 UTC). The last one was M 3.0, 23 km (14 mi) WSW, at 7:09 pm AST on 5 November 2026, estimated intensity II (weak) in town. Every earthquake near Central Aguirre

This page: a magnitude 3.4 earthquake was recorded 16 km (10 mi) south-southeast of Central Aguirre, PR, at 1:33 am AST on 31 July 2022 (05:33 UTC), 7.1 km deep.

USGS: 16 km SSE of Central Aguirre, Puerto Rico

67 km (42 mi) SSW of San Juan, PR · 50 km (31 mi) SSW of Caguas, PR

1:33 am AST, Jul 31, 2022 · · 7.1 km deep · released about 2 tons of TNT

10 km30 km60 km120 km N Guayama Municipio 19 kmSalinas Municipio 19 kmArroyo Municipio 24 kmSanta Isabel Municipio 26 kmPatillas Municipio 30 kmCayey Municipio 33 kmAibonito Municipio 36 kmCoamo Municipio 37 kmMaunabo 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
1:33 am AST on 31 July 2022 ()
Where
16 km (10 mi) south-southeast of Central Aguirre, PR · earthquakes near Central Aguirre
Magnitude
M 3.4 (md)
Depth
7.1 km below the surface
Felt
no reports yet
Nearest
Guayama Municipio, 19 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1491 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 58 km (36 mi) from the epicentre. In Central Aguirre, 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: Guayama 21 km, intensity III · Santa Isabel 28 km, intensity II · Cayey 34 km, intensity II · Coamo 35 km, intensity II · Río Cañas Abajo 39 km, intensity II · Emajagua 39 km, intensity II · Jagual 44 km, intensity II · Sumidero 46 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 2 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.4 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 86,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 3,800× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,700× the energy of this one
  4. This earthquake M 3.4 about 2 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 4.1× 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 4.6 on 2016-12-05 — about 61 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 17.8107, -66.1920. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Guayama Municipio, PR 19 km (12 mi) NNE earthquakes near Guayama Municipio
Salinas Municipio, PR 19 km (12 mi) NNW earthquakes near Salinas Municipio
Arroyo Municipio, PR 24 km (15 mi) NE earthquakes near Arroyo Municipio
Santa Isabel Municipio, PR 26 km (16 mi) NW earthquakes near Santa Isabel Municipio
Patillas Municipio, PR 30 km (19 mi) NE earthquakes near Patillas Municipio
Cayey Municipio, PR 33 km (20 mi) N earthquakes near Cayey Municipio

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

Aftershocks so far

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

  1. 3.4 4 km SSW of Potala Pastillo, Puerto Rico
  2. 3.4 5 km SSW of Potala Pastillo, Puerto Rico
  3. 2.3 2 km SE of Lamboglia, Puerto Rico
  4. 2.3 3 km ESE of Salinas, Puerto Rico
  5. 3.0 6 km SSW of Potala Pastillo, Puerto Rico
  6. 1.9 2 km SSE of Lamboglia, Puerto Rico
  7. 2.4 Puerto Rico region
  8. 2.2 5 km SSW of Potala Pastillo, Puerto Rico
  9. 3.0 3 km ESE of Cayey, Puerto Rico
  10. 3.0 3 km E of Cayey, Puerto Rico
  11. 1.8 2 km SW of G. L. Garcia, Puerto Rico
  12. 2.1 3 km ENE of Mariano Colón, Puerto Rico
  13. 2.0 9 km S of Ponce, Puerto Rico
  14. 2.3 5 km SSW of Potala Pastillo, Puerto Rico
  15. 2.2 7 km S of Ponce, 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.