QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Guayanilla, PR

No earthquake was likely felt in Guayanilla in the 24 hours to 12:59 pm AST (16:59 UTC). The last one was M 2.1, in Guayanilla, at 4:39 pm AST on 9 November 2026, estimated intensity II (weak) in town. Every earthquake near Guayanilla

This page: a magnitude 1.8 earthquake was recorded 4 km (2 mi) northwest of Guayanilla, PR, at 1:16 pm AST on 9 August 2019 (17:16 UTC), 12 km deep.

USGS: 3 km NW of Guayanilla, Puerto Rico

21 km (13 mi) WNW of Ponce, PR

1:16 pm AST, Aug 9, 2019 · · 12 km deep · released about 16 lb of TNT

Every earthquake near Guayanilla Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Guayanilla Municipio 5 kmYauco Municipio 6 kmPeñuelas Municipio 9 kmSabana Grande Municipio 15 kmGuánica Municipio 16 kmAdjuntas Municipio 16 kmMaricao Municipio 19 kmPonce Municipio 22 kmSan Germán Municipio 25 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
1:16 pm AST on 9 August 2019 ()
Where
4 km (2 mi) northwest of Guayanilla, PR · earthquakes near Guayanilla
Magnitude
M 1.8 (md)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Guayanilla Municipio, 5 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2651 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 7 km (4 mi) from the epicentre. In Guayanilla, 4 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: Guayanilla 4 km, intensity II · Yauco 4 km, intensity II · Magas Arriba 6 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 16 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 5.8 930,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 660,000× the energy of this one
  3. Around the size people start to feel M 3.0 59× the energy of this one
  4. This earthquake M 1.8 about 16 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 · 48 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 18.0463, -66.8136. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Guayanilla Municipio, PR 5 km (3 mi) SSE earthquakes near Guayanilla Municipio
Yauco Municipio, PR 6 km (4 mi) NW earthquakes near Yauco Municipio
Peñuelas Municipio, PR 9 km (6 mi) ESE earthquakes near Peñuelas Municipio
Sabana Grande Municipio, PR 15 km (9 mi) WNW earthquakes near Sabana Grande Municipio
Guánica Municipio, PR 16 km (10 mi) SW earthquakes near Guánica Municipio
Adjuntas Municipio, PR 16 km (10 mi) NNE earthquakes near Adjuntas Municipio

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

Aftershocks so far

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

  1. 2.7 3 km WNW of Mayagüez, Puerto Rico
  2. 1.9 3 km SSW of Palmarejo, Puerto Rico
  3. 1.9 5 km NE of Sabana Grande, Puerto Rico
  4. 1.8 11 km SSE of Ponce, Puerto Rico
  5. 2.2 2 km S of Palmarejo, Puerto Rico
  6. 1.9 5 km WNW of Mayagüez, Puerto Rico
  7. 2.0 2 km NNW of Hormigueros, Puerto Rico
  8. 2.0 3 km NW of La Parguera, Puerto Rico
  9. 1.6 5 km SE of La Parguera, Puerto Rico
  10. 2.2 1 km S of Río Cañas Abajo, Puerto Rico
  11. 1.9 Puerto Rico region
  12. 1.5 Mona Passage
  13. 2.1 8 km ESE of Maricao, Puerto Rico
  14. 2.4 6 km W of Hormigueros, Puerto Rico
  15. 1.9 3 km S 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.