QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

Earthquake near Adjuntas, PR

No earthquake was likely felt in Adjuntas in the 24 hours to 7:52 pm AST (23:52 UTC). The last one was M 3.0, 31 km (19 mi) SSW, at 3:45 am AST on 8 November 2026, estimated intensity II (weak) in town. Every earthquake near Adjuntas

This page: a magnitude 2.3 earthquake was recorded 5 km (3 mi) south-southeast of Adjuntas, PR, at 3:49 am AST on 28 July 2023 (07:49 UTC), 22 km deep.

USGS: 4 km SSE of Adjuntas, Puerto Rico

16 km (10 mi) NW of Ponce, PR

3:49 am AST, Jul 28, 2023 · · 22 km deep · released about 82 lb of TNT

Every earthquake near Adjuntas Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Adjuntas Municipio 8 kmPeñuelas Municipio 11 kmGuayanilla Municipio 16 kmYauco Municipio 16 kmJayuya Municipio 16 kmUtuado Municipio 17 kmPonce Municipio 17 kmLares Municipio 24 kmMaricao 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
3:49 am AST on 28 July 2023 ()
Where
5 km (3 mi) south-southeast of Adjuntas, PR · earthquakes near Adjuntas
Magnitude
M 2.3 (md)
Depth
22 km below the surface
Felt
no reports yet
Nearest
Adjuntas Municipio, 8 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1203 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Adjuntas, 5 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.

Earthquakes near other towns within 30 km: Peñuelas, Santo Domingo, Tallaboa Alta, Magas Arriba, Tallaboa, Guayanilla.

How big was it?

This earthquake released about 82 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 180,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 130,000× the energy of this one
  3. Around the size people start to feel M 3.0 12× the energy of this one
  4. This earthquake M 2.3 about 82 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 6.4 on 2020-01-07 — about 1,500,000 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 · 49 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 18.1222, -66.7115. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Adjuntas Municipio, PR 8 km (5 mi) NW earthquakes near Adjuntas Municipio
Peñuelas Municipio, PR 11 km (7 mi) S earthquakes near Peñuelas Municipio
Guayanilla Municipio, PR 16 km (10 mi) SW earthquakes near Guayanilla Municipio
Yauco Municipio, PR 16 km (10 mi) WSW earthquakes near Yauco Municipio
Jayuya Municipio, PR 16 km (10 mi) NE earthquakes near Jayuya Municipio
Utuado Municipio, PR 17 km (10 mi) N earthquakes near Utuado Municipio

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

Aftershocks so far

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

  1. 2.3 5 km WSW of Fuig, Puerto Rico
  2. 2.4 7 km ESE of La Parguera, Puerto Rico
  3. 2.9 5 km SE of Maria Antonia, Puerto Rico
  4. 2.5 4 km WNW of Coto Laurel, Puerto Rico
  5. 2.4 1 km SW of Indios, Puerto Rico
  6. 2.4 8 km SE of La Parguera, Puerto Rico
  7. 1.7 Puerto Rico region
  8. 2.3 1 km NW of Guayanilla, Puerto Rico
  9. 2.7 Puerto Rico region
  10. 2.1 1 km WSW of Guayanilla, Puerto Rico
  11. 2.0 1 km ENE of Indios, Puerto Rico
  12. 2.1 8 km SSE of Maria Antonia, Puerto Rico
  13. 2.2 4 km SSW of Indios, Puerto Rico
  14. 1.6 2 km NNW of La Parguera, Puerto Rico
  15. 2.2 7 km WSW of La Parguera, 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.