QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

Earthquake near Adjuntas, PR

No earthquake was likely felt in Adjuntas in the 24 hours to 11:27 am AST (15:27 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 1.6 earthquake was recorded 9 km (5 mi) west of Adjuntas, PR, at 11:51 am AST on 18 September 2019 (15:51 UTC), 7.0 km deep.

USGS: 8 km W of Adjuntas, Puerto Rico

27 km (17 mi) NW of Ponce, PR

11:51 am AST, Sep 18, 2019 · · 7.0 km deep · released about 8.7 lb of TNT

10 km30 km60 km120 km N Adjuntas Municipio 5 kmYauco Municipio 11 kmLares Municipio 14 kmMaricao Municipio 14 kmUtuado Municipio 15 kmPeñuelas Municipio 18 kmSabana Grande Municipio 18 kmGuayanilla Municipio 19 kmLas Marías Municipio 19 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
11:51 am AST on 18 September 2019 ()
Where
9 km (5 mi) west of Adjuntas, PR · earthquakes near Adjuntas
Magnitude
M 1.6 (md)
Depth
7.0 km below the surface
Felt
no reports yet
Nearest
Adjuntas Municipio, 5 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2611 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 9 km (6 mi) from the epicentre. In Adjuntas, 9 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 9 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 8.7 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,200,000× the energy of this one
  3. Around the size people start to feel M 3.0 110× the energy of this one
  4. This earthquake M 1.6 about 8.7 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 · 38 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 18.1731, -66.8033. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Adjuntas Municipio, PR 5 km (3 mi) E earthquakes near Adjuntas Municipio
Yauco Municipio, PR 11 km (7 mi) SSW earthquakes near Yauco Municipio
Lares Municipio, PR 14 km (8 mi) NNW earthquakes near Lares Municipio
Maricao Municipio, PR 14 km (9 mi) W earthquakes near Maricao Municipio
Utuado Municipio, PR 15 km (9 mi) NE earthquakes near Utuado Municipio
Peñuelas Municipio, PR 18 km (11 mi) SSE earthquakes near Peñuelas 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. 1.8 4 km WNW of Hormigueros, Puerto Rico
  2. 2.0 12 km S of Ponce, Puerto Rico
  3. 2.6 4 km NNE of Isabela, Puerto Rico
  4. 1.6 6 km WSW of Guánica, Puerto Rico
  5. 1.6 12 km SSE of Ponce, Puerto Rico
  6. 1.5 3 km WNW of Palmarejo, Puerto Rico
  7. 2.0 3 km SW of San Sebastián, Puerto Rico
  8. 2.2 7 km S of La Parguera, Puerto Rico
  9. 1.6 10 km SSW of Potala Pastillo, Puerto Rico
  10. 1.8 12 km SSE of Ponce, Puerto Rico
  11. 2.9 10 km NNW of Camuy, Puerto Rico
  12. 2.3 8 km SE of Tallaboa, Puerto Rico
  13. 1.8 1 km E of Lluveras, Puerto Rico
  14. 1.6 4 km ESE of Boquerón, Puerto Rico
  15. 2.0 1 km SE of Maricao, 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.