QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0md

Earthquake near Bayamón, PR

No earthquake was likely felt in Bayamón in the 24 hours to 10:13 am AST (14:13 UTC). The last one was M 4.8, 98 km (61 mi) WSW, at 9:19 am AST on 18 September 2026, estimated intensity III (weak) in town; 86 felt reports to USGS. Every earthquake near Bayamón

This page: a magnitude 3.0 earthquake was recorded 25 km (15 mi) south-southeast of Bayamón, PR, at 9:11 pm AST on 4 July 2023 (01:11 UTC), 12 km deep. 2 people have reported feeling it to USGS.

USGS: 1 km ENE of Bayamon, Puerto Rico

9 km (5 mi) SW of Caguas, PR

9:11 pm AST, Jul 4, 2023 · · 12 km deep · released about 860 lb of TNT

Every earthquake near Bayamón Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Cidra Municipio 6 kmCaguas Municipio 6 kmAguas Buenas Municipio 9 kmCayey Municipio 10 kmComerío Municipio 13 kmSan Lorenzo Municipio 14 kmGurabo Municipio 16 kmGuaynabo Municipio 18 kmAibonito Municipio 18 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
9:11 pm AST on 4 July 2023 ()
Where
25 km (15 mi) south-southeast of Bayamón, PR · earthquakes near Bayamón
Magnitude
M 3.0 (md)
Depth
12 km below the surface
Felt
2 reports · strongest reported intensity II
Nearest
Cidra Municipio, 6 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1225 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 33 km (21 mi) from the epicentre. In Bayamón, 25 km away, the estimate is intensity II (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: Sumidero 5 km, intensity III · Caguas 8 km, intensity III · Cayey 10 km, intensity III · Jagual 12 km, intensity III · Guaynabo 19 km, intensity II · Trujillo Alto 22 km, intensity II · Guayama 22 km, intensity II · Bayamón 25 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 860 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 390,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 18,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 12,000× the energy of this one
  4. This earthquake M 3.0 about 860 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 280 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 · 9 km NNW of this epicentre
  2. 5.0 3 km N of Brenas, Puerto Rico · 43 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 18.1835, -66.1035. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Cidra Municipio, PR 6 km (4 mi) W earthquakes near Cidra Municipio
Caguas Municipio, PR 6 km (4 mi) ENE earthquakes near Caguas Municipio
Aguas Buenas Municipio, PR 9 km (5 mi) NNW earthquakes near Aguas Buenas Municipio
Cayey Municipio, PR 10 km (6 mi) SSW earthquakes near Cayey Municipio
Comerío Municipio, PR 13 km (8 mi) WNW earthquakes near Comerío Municipio
San Lorenzo Municipio, PR 14 km (9 mi) ESE earthquakes near San Lorenzo Municipio

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

Aftershocks so far

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

  1. 2.3 5 km SSE of Salinas, Puerto Rico
  2. 2.4 3 km SSE of Salinas, Puerto Rico
  3. 2.3 Puerto Rico region
  4. 3.3 4 km ENE of Guaynabo, Puerto Rico
  5. 2.6 Puerto Rico region
  6. 2.6 8 km S of Orocovis, Puerto Rico
  7. 3.1 10 km S of Lamboglia, Puerto Rico
  8. 2.3 3 km S of Las Ochenta, Puerto Rico
  9. 2.4 4 km WSW of Central Aguirre, Puerto Rico
  10. 2.5 Puerto Rico region
  11. 2.7 4 km S of Salinas, Puerto Rico
  12. 2.3 4 km SSE of Salinas, Puerto Rico
  13. 1.9 Puerto Rico region
  14. 3.3 Puerto Rico region
  15. 2.4 15 km SSE of Central Aguirre, 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.