QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8md

Earthquake near Adjuntas, PR

No earthquake was likely felt in Adjuntas in the 24 hours to 10:42 am AST (14:42 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 2.8 earthquake was recorded 2 km (1 mi) south-southwest of Adjuntas, PR, at 8:12 am AST on 23 July 2023 (12:12 UTC), 20 km deep. 1 person has reported feeling it to USGS.

USGS: 2 km SSW of Adjuntas, Puerto Rico

19 km (12 mi) NW of Ponce, PR

8:12 am AST, Jul 23, 2023 · · 20 km deep · released about 400 lb of TNT

Every earthquake near Adjuntas Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Adjuntas Municipio 5 kmPeñuelas Municipio 13 kmUtuado Municipio 14 kmYauco Municipio 15 kmJayuya Municipio 17 kmGuayanilla Municipio 17 kmPonce Municipio 20 kmLares Municipio 21 kmMaricao Municipio 22 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
8:12 am AST on 23 July 2023 ()
Where
2 km (1 mi) south-southwest of Adjuntas, PR · earthquakes near Adjuntas
Magnitude
M 2.8 (md)
Depth
20 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Adjuntas Municipio, 5 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1028 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 17 km (11 mi) from the epicentre. In Adjuntas, 2 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: Adjuntas 2 km, intensity II · Tallaboa Alta 11 km, intensity II · Magas Arriba 15 km, intensity II · Guayanilla 15 km, intensity II · Jayuya 17 km, intensity II · Tallaboa 17 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 400 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 38,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 27,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.4× the energy of this one
  4. This earthquake M 2.8 about 400 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 300,000 times the energy of this one.

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

  1. 5.8 12 km N of Garrochales, Puerto Rico · 50 km NNE of this epicentre
  2. 5.8 4 km E of Moca, Puerto Rico · 46 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 18.1437, -66.7268. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Adjuntas Municipio, PR 5 km (3 mi) NW earthquakes near Adjuntas Municipio
Peñuelas Municipio, PR 13 km (8 mi) S earthquakes near Peñuelas Municipio
Utuado Municipio, PR 14 km (9 mi) N earthquakes near Utuado Municipio
Yauco Municipio, PR 15 km (9 mi) WSW earthquakes near Yauco Municipio
Jayuya Municipio, PR 17 km (10 mi) ENE earthquakes near Jayuya Municipio
Guayanilla Municipio, PR 17 km (11 mi) SSW earthquakes near Guayanilla Municipio

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

Aftershocks so far

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

  1. 2.6 2 km SSW of Las Marías, Puerto Rico
  2. 2.8 0 km E of Palomas, Puerto Rico
  3. 2.3 2 km SW of Indios, Puerto Rico
  4. 2.4 5 km E of La Parguera, Puerto Rico
  5. 2.8 8 km SE of La Parguera, Puerto Rico
  6. 2.6 3 km WSW of La Parguera, Puerto Rico
  7. 2.4 8 km SW of La Parguera, Puerto Rico
  8. 2.0 3 km S of Guánica, Puerto Rico
  9. 2.4 2 km SW of Indios, Puerto Rico
  10. 2.6 2 km SSW of Guánica, Puerto Rico
  11. 2.1 7 km WSW of Guánica, Puerto Rico
  12. 2.5 Puerto Rico region
  13. 2.0 7 km SSE of Guánica, Puerto Rico
  14. 2.5 Puerto Rico region
  15. 1.8 7 km ESE of Pole Ojea, 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.