QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Hormigueros, PR

No earthquake was likely felt in Hormigueros in the 24 hours to 4:38 pm AST (20:38 UTC). The last one was M 2.1, 15 km (9 mi) S, at 11:57 pm AST on 8 November 2026, estimated intensity II (weak) in town. Every earthquake near Hormigueros

This page: a magnitude 1.8 earthquake was recorded 3 km (2 mi) southwest of Hormigueros, PR, at 3:29 am AST on 18 September 2019 (07:29 UTC), 11 km deep.

USGS: 3 km SW of Hormigueros, Puerto Rico

9 km (6 mi) S of Mayagüez, PR · 119 km (74 mi) WSW of San Juan, PR

3:29 am AST, Sep 18, 2019 · · 11 km deep · released about 17 lb of TNT

Every earthquake near Hormigueros Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Hormigueros Municipio 4 kmSan Germán Municipio 12 kmCabo Rojo Municipio 14 kmAñasco Municipio 19 kmLajas Municipio 19 kmSabana Grande Municipio 22 kmLas Marías Municipio 22 kmMaricao Municipio 23 kmRincón Municipio 27 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
3:29 am AST on 18 September 2019 ()
Where
3 km (2 mi) southwest of Hormigueros, PR · earthquakes near Hormigueros
Magnitude
M 1.8 (md)
Depth
11 km below the surface
Felt
no reports yet
Nearest
Hormigueros Municipio, 4 km ENE
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 Hormigueros, 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.

Likely felt in: Puerto Real 7 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 17 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 5.8 870,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 620,000× the energy of this one
  3. Around the size people start to feel M 3.0 55× the energy of this one
  4. This earthquake M 1.8 about 17 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 4.3 on 2019-09-05 — about 4,900 times the energy of this one.

Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:

  1. 6.3 6 km WNW of Aguadilla, Puerto Rico · 36 km N of this epicentre
  2. 6.1 15 km WNW of San Antonio, Puerto Rico · 49 km N of this epicentre
  3. 5.8 4 km E of Moca, Puerto Rico · 32 km NNE of this epicentre
  4. 5.2 19 km SW of Stella, Puerto Rico · 25 km WNW of this epicentre
  5. 5.1 21 km SW of Stella, Puerto Rico · 24 km WNW 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 18.1206, -67.1478. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Hormigueros Municipio, PR 4 km (2 mi) ENE earthquakes near Hormigueros Municipio
San Germán Municipio, PR 12 km (7 mi) E earthquakes near San Germán Municipio
Cabo Rojo Municipio, PR 14 km (9 mi) SSW earthquakes near Cabo Rojo Municipio
Añasco Municipio, PR 19 km (12 mi) N earthquakes near Añasco Municipio
Lajas Municipio, PR 19 km (12 mi) SE earthquakes near Lajas Municipio
Sabana Grande Municipio, PR 22 km (13 mi) E earthquakes near Sabana Grande Municipio

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

Aftershocks so far

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

  1. 1.8 7 km WNW of Puerto Real, Puerto Rico
  2. 2.3 7 km WSW of Guánica, Puerto Rico
  3. 2.4 37 km W of Puerto Real, Puerto Rico
  4. 1.6 3 km WSW of Fuig, Puerto Rico
  5. 1.9 2 km SW of Adjuntas, Puerto Rico
  6. 1.7 13 km WSW of Pole Ojea, Puerto Rico
  7. 2.1 14 km SSE of Guánica, Puerto Rico
  8. 2.0 2 km NNE of Sabana Grande, Puerto Rico
  9. 1.8 4 km WNW of Hormigueros, Puerto Rico
  10. 2.6 4 km NNE of Isabela, Puerto Rico
  11. 1.6 6 km WSW of Guánica, Puerto Rico
  12. 1.5 3 km WNW of Palmarejo, Puerto Rico
  13. 2.3 8 km NW of Caban, Puerto Rico
  14. 2.0 3 km SW of San Sebastián, Puerto Rico
  15. 2.2 7 km S of La Parguera, 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.