QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6Md

Earthquake near Hormigueros, PR

No earthquake was likely felt in Hormigueros in the 24 hours to 8:45 pm AST (00:45 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 1.6 earthquake was recorded 2 km (2 mi) south-southwest of Hormigueros, PR, at 6:43 pm AST on 4 November 2016 (22:43 UTC), 19 km deep.

USGS: 2 km SSW of Hormigueros, Puerto Rico

9 km (6 mi) S of Mayagüez, PR · 118 km (73 mi) WSW of San Juan, PR

6:43 pm AST, Nov 4, 2016 · · 19 km deep · released about 7.6 lb of TNT

Every earthquake near Hormigueros Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Hormigueros Municipio 3 kmSan Germán Municipio 11 kmCabo Rojo Municipio 14 kmAñasco Municipio 18 kmLajas Municipio 19 kmSabana Grande Municipio 21 kmLas Marías Municipio 21 kmMaricao Municipio 22 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
6:43 pm AST on 4 November 2016 ()
Where
2 km (2 mi) south-southwest of Hormigueros, PR · earthquakes near Hormigueros
Magnitude
M 1.6 (Md)
Depth
19 km below the surface
Felt
no reports yet
Nearest
Hormigueros Municipio, 3 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3659 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 Hormigueros, 2 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: Cabo Rojo, Monte Grande, Puerto Real, Sabana Eneas, Mayagüez, Boquerón.

How big was it?

This earthquake released about 7.6 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 2,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.6 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 5 earthquakes of M5 or more within 50 km:

  1. 6.3 6 km WNW of Aguadilla, Puerto Rico · 36 km NNW of this epicentre
  2. 6.1 15 km WNW of San Antonio, Puerto Rico · 49 km NNW 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 · 25 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 18.1210, -67.1398. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Hormigueros Municipio, PR 3 km (2 mi) ENE earthquakes near Hormigueros Municipio
San Germán Municipio, PR 11 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 18 km (11 mi) N earthquakes near Añasco Municipio
Lajas Municipio, PR 19 km (12 mi) SSE earthquakes near Lajas Municipio
Sabana Grande Municipio, PR 21 km (13 mi) ESE earthquakes near Sabana Grande Municipio

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

Aftershocks so far

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

  1. 2.6 5 km WSW of La Parguera, Puerto Rico
  2. 2.4 8 km SSE of La Parguera, Puerto Rico
  3. 2.3 20 km S of La Parguera, Puerto Rico
  4. 2.3 13 km SSW of Guánica, Puerto Rico
  5. 2.4 1 km W of San Germán, Puerto Rico
  6. 2.3 13 km WNW of Rincón, Puerto Rico
  7. 1.7 1 km WNW of Monte Grande, Puerto Rico
  8. 1.9 12 km SSE of Lares, Puerto Rico
  9. 2.0 20 km SSW of Guánica, Puerto Rico
  10. 2.5 11 km NW of Puerto Real, Puerto Rico
  11. 1.9 3 km ESE of Las Marías, Puerto Rico
  12. 2.3 10 km NNW of Puerto Real, Puerto Rico
  13. 2.7 6 km NNW of Santo Domingo, Puerto Rico
  14. 2.4 8 km WSW of Mayagüez, Puerto Rico
  15. 1.6 5 km SSW of Adjuntas, 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.