QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

Earthquake near Adjuntas, PR

No earthquake was likely felt in Adjuntas in the 24 hours to 3:47 pm AST (19:47 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 1.9 earthquake was recorded 3 km (2 mi) south of Adjuntas, PR, at 11:33 am AST on 4 September 2019 (15:33 UTC), 20 km deep.

USGS: 2 km S of Adjuntas, Puerto Rico

19 km (12 mi) NW of Ponce, PR

11:33 am AST, Sep 4, 2019 · · 20 km deep · released about 24 lb of TNT

10 km30 km60 km120 km N Adjuntas Municipio 6 kmPeñuelas Municipio 13 kmUtuado Municipio 15 kmYauco Municipio 15 kmJayuya Municipio 16 kmGuayanilla Municipio 17 kmPonce Municipio 20 kmLares Municipio 22 kmMaricao Municipio 23 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
11:33 am AST on 4 September 2019 ()
Where
3 km (2 mi) south of Adjuntas, PR · earthquakes near Adjuntas
Magnitude
M 1.9 (md)
Depth
20 km below the surface
Felt
no reports yet
Nearest
Adjuntas Municipio, 6 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2625 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, 3 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: Santo Domingo, Peñuelas, Tallaboa Alta, Utuado, Magas Arriba, Guayanilla.

How big was it?

This earthquake released about 24 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 640,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 450,000× the energy of this one
  3. Around the size people start to feel M 3.0 40× the energy of this one
  4. This earthquake M 1.9 about 24 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

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 · 47 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 18.1396, -66.7231. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Adjuntas Municipio, PR 6 km (4 mi) NW earthquakes near Adjuntas Municipio
Peñuelas Municipio, PR 13 km (8 mi) S earthquakes near Peñuelas Municipio
Utuado Municipio, PR 15 km (9 mi) N earthquakes near Utuado Municipio
Yauco Municipio, PR 15 km (10 mi) WSW earthquakes near Yauco Municipio
Jayuya Municipio, PR 16 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

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

  1. 2.2 3 km ESE of Maricao, Puerto Rico
  2. 1.9 2 km SSE of Mayagüez, Puerto Rico
  3. 2.1 7 km SE of Espino, Puerto Rico
  4. 1.6 6 km WSW of Liborio Negron Torres, Puerto Rico
  5. 1.9 4 km WNW of La Parguera, Puerto Rico
  6. 1.6 0 km NE of Guayanilla, Puerto Rico
  7. 1.7 0 km WSW of Magas Arriba, Puerto Rico
  8. 1.8 11 km SSE of La Parguera, Puerto Rico
  9. 1.6 2 km NW of Maricao, Puerto Rico
  10. 1.8 4 km ESE of Boquerón, Puerto Rico
  11. 2.5 4 km SSE of Cacao, Puerto Rico
  12. 1.9 3 km SW of San Sebastián, Puerto Rico
  13. 2.0 7 km SW of Guánica, Puerto Rico
  14. 2.3 10 km SW of Guánica, Puerto Rico
  15. 1.5 2 km E of Mayagüez, 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.