QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7Md

Earthquake near Monte Grande, PR

No earthquake was likely felt in Monte Grande in the 24 hours to 1:38 am AST (05:38 UTC). The last one was M 2.1, 9 km (6 mi) S, at 11:57 pm AST on 8 November 2026, estimated intensity II (weak) in town. Every earthquake near Monte Grande

This page: a magnitude 2.7 earthquake was recorded in Monte Grande, PR, at 10:28 pm AST on 29 March 2017 (02:28 UTC), 26 km deep.

USGS: 1 km NW of Monte Grande, Puerto Rico

12 km (7 mi) SSE of Mayagüez, PR · 116 km (72 mi) WSW of San Juan, PR

10:28 pm AST, Mar 29, 2017 · · 26 km deep · released about 340 lb of TNT

Every earthquake near Monte Grande Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Hormigueros Municipio 4 kmSan Germán Municipio 9 kmCabo Rojo Municipio 13 kmLajas Municipio 16 kmSabana Grande Municipio 18 kmLas Marías Municipio 21 kmAñasco Municipio 21 kmMaricao Municipio 21 kmGuánica 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
10:28 pm AST on 29 March 2017 ()
Where
in Monte Grande, PR · earthquakes near Monte Grande
Magnitude
M 2.7 (Md)
Depth
26 km below the surface
Felt
no reports yet
Nearest
Hormigueros Municipio, 4 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3514 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. 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, Sabana Eneas, Hormigueros, Puerto Real, Palmarejo, San Germán.

How big was it?

This earthquake released about 340 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 45,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 32,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.8× the energy of this one
  4. This earthquake M 2.7 about 340 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 4 earthquakes of M5 or more within 50 km:

  1. 6.3 6 km WNW of Aguadilla, Puerto Rico · 39 km NNW of this epicentre
  2. 5.8 4 km E of Moca, Puerto Rico · 34 km N of this epicentre
  3. 5.2 19 km SW of Stella, Puerto Rico · 28 km WNW of this epicentre
  4. 5.1 21 km SW of Stella, Puerto Rico · 28 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 18.0984, -67.1179. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Hormigueros Municipio, PR 4 km (3 mi) N earthquakes near Hormigueros Municipio
San Germán Municipio, PR 9 km (5 mi) E earthquakes near San Germán Municipio
Cabo Rojo Municipio, PR 13 km (8 mi) SSW earthquakes near Cabo Rojo Municipio
Lajas Municipio, PR 16 km (10 mi) SSE earthquakes near Lajas Municipio
Sabana Grande Municipio, PR 18 km (11 mi) E earthquakes near Sabana Grande Municipio
Las Marías Municipio, PR 21 km (13 mi) NE earthquakes near Las Marías 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. 2.3 11 km SSE of Guánica, Puerto Rico
  2. 2.1 3 km N of Monte Grande, Puerto Rico
  3. 2.0 33 km S of Pole Ojea, Puerto Rico
  4. 2.4 1 km W of Palmarejo, Puerto Rico
  5. 1.6 9 km S of La Parguera, Puerto Rico
  6. 1.9 4 km NNW of Puerto Real, Puerto Rico
  7. 2.7 1 km ENE of Mayagüez, Puerto Rico
  8. 2.0 2 km WSW of Sabana Grande, Puerto Rico
  9. 2.3 3 km SSE of La Parguera, Puerto Rico
  10. 1.9 9 km SW of La Parguera, Puerto Rico
  11. 2.3 9 km SW of Guánica, Puerto Rico
  12. 2.5 19 km WNW of Rincón, Puerto Rico
  13. 2.7 19 km SW of Stella, Puerto Rico
  14. 1.6 3 km SW of Mayagüez, Puerto Rico
  15. 2.3 1 km NW of Liborio Negron Torres, 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.