QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Adjuntas, PR

No earthquake was likely felt in Adjuntas in the 24 hours to 11:29 am AST (15:29 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 1.8 earthquake was recorded 8 km (5 mi) west-southwest of Adjuntas, PR, at 4:56 am AST on 8 December 2019 (08:56 UTC), 14 km deep.

USGS: 7 km WSW of Adjuntas, Puerto Rico

24 km (15 mi) NW of Ponce, PR

4:56 am AST, Dec 8, 2019 · · 14 km deep · released about 14 lb of TNT

Every earthquake near Adjuntas Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Adjuntas Municipio 6 kmYauco Municipio 10 kmPeñuelas Municipio 14 kmGuayanilla Municipio 15 kmMaricao Municipio 16 kmUtuado Municipio 17 kmLares Municipio 17 kmSabana Grande Municipio 18 kmLas Marías 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
4:56 am AST on 8 December 2019 ()
Where
8 km (5 mi) west-southwest of Adjuntas, PR · earthquakes near Adjuntas
Magnitude
M 1.8 (md)
Depth
14 km below the surface
Felt
no reports yet
Nearest
Adjuntas Municipio, 6 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2530 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, 8 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, Yauco, Guayanilla, Tallaboa Alta, Magas Arriba.

How big was it?

This earthquake released about 14 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 790,000× the energy of this one
  3. Around the size people start to feel M 3.0 70× the energy of this one
  4. This earthquake M 1.8 about 14 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 one earthquake of M5 or more within 50 km:

  1. 5.8 4 km E of Moca, Puerto Rico · 41 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 18.1418, -66.7896. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Adjuntas Municipio, PR 6 km (3 mi) NE earthquakes near Adjuntas Municipio
Yauco Municipio, PR 10 km (6 mi) SW earthquakes near Yauco Municipio
Peñuelas Municipio, PR 14 km (9 mi) SSE earthquakes near Peñuelas Municipio
Guayanilla Municipio, PR 15 km (9 mi) S earthquakes near Guayanilla Municipio
Maricao Municipio, PR 16 km (10 mi) WNW earthquakes near Maricao Municipio
Utuado Municipio, PR 17 km (11 mi) NNE earthquakes near Utuado Municipio

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

Aftershocks so far

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

  1. 2.3 12 km SSE of Ponce, Puerto Rico
  2. 1.8 12 km SSE of Ponce, Puerto Rico
  3. 2.5 12 km SSE of Ponce, Puerto Rico
  4. 2.1 11 km SSE of Ponce, Puerto Rico
  5. 2.3 10 km S of Ponce, Puerto Rico
  6. 2.5 11 km SSE of Ponce, Puerto Rico
  7. 2.2 11 km SSE of Ponce, Puerto Rico
  8. 1.9 12 km SW of Potala Pastillo, Puerto Rico
  9. 1.8 11 km SSW of Potala Pastillo, Puerto Rico
  10. 2.0 11 km SW of Potala Pastillo, Puerto Rico
  11. 2.9 13 km SSE of Ponce, Puerto Rico
  12. 1.8 10 km S of Ponce, Puerto Rico
  13. 1.8 3 km N of Las Marías, Puerto Rico
  14. 2.6 7 km NNE of Animas, Puerto Rico
  15. 2.0 12 km SW of Potala Pastillo, 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.