QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9md

Earthquake near Arecibo, PR

No earthquake was likely felt in Arecibo in the 24 hours to 10:10 am AST (14:10 UTC). The last one was M 3.4, 49 km (31 mi) NW, at 9:00 pm AST on 27 October 2026, estimated intensity II (weak) in town. Every earthquake near Arecibo

This page: a magnitude 2.9 earthquake was recorded 15 km (10 mi) west-northwest of Arecibo, PR, at 1:30 am AST on 2 August 2023 (05:30 UTC), 19 km deep.

USGS: Puerto Rico region

15 km (9 mi) NW of Arecibo, PR · 83 km (52 mi) W of San Juan, PR

1:30 am AST, Aug 2, 2023 · · 19 km deep · released about 650 lb of TNT

Every earthquake near Arecibo Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Camuy Municipio 11 kmHatillo Municipio 12 kmQuebradillas Municipio 13 kmIsabela Municipio 20 kmArecibo Municipio 21 kmSan Sebastián Municipio 27 kmLares Municipio 30 kmBarceloneta Municipio 31 kmMoca Municipio 31 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
1:30 am AST on 2 August 2023 ()
Where
15 km (10 mi) west-northwest of Arecibo, PR · earthquakes near Arecibo
Magnitude
M 2.9 (md)
Depth
19 km below the surface
Felt
no reports yet
Nearest
Camuy Municipio, 11 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1197 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 25 km (16 mi) from the epicentre. In Arecibo, 15 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: Hatillo 7 km, intensity II · Quebradillas 13 km, intensity II · Arecibo 15 km, intensity II · Isabela 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 650 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 23,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 16,000× 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 650 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 in our catalogue was M 4.2 on 2022-12-30 — about 86 times the energy of this one.

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 18.5457, -66.8397. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Camuy Municipio, PR 11 km (7 mi) SSW earthquakes near Camuy Municipio
Hatillo Municipio, PR 12 km (8 mi) SSE earthquakes near Hatillo Municipio
Quebradillas Municipio, PR 13 km (8 mi) SW earthquakes near Quebradillas Municipio
Isabela Municipio, PR 20 km (12 mi) WSW earthquakes near Isabela Municipio
Arecibo Municipio, PR 21 km (13 mi) SE earthquakes near Arecibo Municipio
San Sebastián Municipio, PR 27 km (17 mi) SSW earthquakes near San Sebastián Municipio

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

Aftershocks so far

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

  1. 2.9 4 km NW of Maricao, Puerto Rico
  2. 2.5 3 km S of Quebrada, Puerto Rico
  3. 2.4 1 km N of Quebrada, Puerto Rico
  4. 2.7 11 km N of Arecibo, Puerto Rico
  5. 2.8 31 km N of Isabela, Puerto Rico
  6. 3.0 Puerto Rico region
  7. 2.2 Puerto Rico region
  8. 3.1 15 km NNE of Carrizales, Puerto Rico
  9. 3.0 0 km SW of Maricao, Puerto Rico
  10. 2.2 5 km N of Sabana Grande, Puerto Rico
  11. 2.8 5 km NNW of Mayagüez, Puerto Rico
  12. 3.4 48 km N of Hatillo, Puerto Rico
  13. 3.1 18 km NNW of Camuy, Puerto Rico
  14. 3.2 21 km N of Quebradillas, Puerto Rico
  15. 3.8 39 km N of Carrizales, 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.