QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Monte Grande, PR

No earthquake was likely felt in Monte Grande in the 24 hours to 6:02 pm AST (22:02 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 1.7 earthquake was recorded 3 km (2 mi) south-southeast of Monte Grande, PR, at 10:29 pm AST on 25 August 2017 (02:29 UTC), 26 km deep.

USGS: 3 km SSE of Monte Grande, Puerto Rico

16 km (10 mi) SSE of Mayagüez, PR · 116 km (72 mi) WSW of San Juan, PR

10:29 pm AST, Aug 25, 2017 · · 26 km deep · released about 12 lb of TNT

Every earthquake near Monte Grande Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Germán Municipio 8 kmHormigueros Municipio 8 kmLajas Municipio 11 kmCabo Rojo Municipio 11 kmSabana Grande Municipio 16 kmMaricao Municipio 21 kmGuánica Municipio 22 kmLas Marías Municipio 22 kmAñasco 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
10:29 pm AST on 25 August 2017 ()
Where
3 km (2 mi) south-southeast of Monte Grande, PR · earthquakes near Monte Grande
Magnitude
M 1.7 (md)
Depth
26 km below the surface
Felt
no reports yet
Nearest
San Germán Municipio, 8 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3365 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 Monte Grande, 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.

Earthquakes near other towns within 30 km: Palmarejo, Sabana Eneas, Lajas, Cabo Rojo, San Germán, Boquerón.

How big was it?

This earthquake released about 12 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 870,000× the energy of this one
  3. Around the size people start to feel M 3.0 78× the energy of this one
  4. This earthquake M 1.7 about 12 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 · 44 km NNW of this epicentre
  2. 5.8 4 km E of Moca, Puerto Rico · 38 km N of this epicentre
  3. 5.2 19 km SW of Stella, Puerto Rico · 32 km WNW of this epicentre
  4. 5.1 21 km SW of Stella, Puerto Rico · 31 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 18.0615, -67.0980. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Germán Municipio, PR 8 km (5 mi) NE earthquakes near San Germán Municipio
Hormigueros Municipio, PR 8 km (5 mi) NNW earthquakes near Hormigueros Municipio
Lajas Municipio, PR 11 km (7 mi) SSE earthquakes near Lajas Municipio
Cabo Rojo Municipio, PR 11 km (7 mi) SW earthquakes near Cabo Rojo Municipio
Sabana Grande Municipio, PR 16 km (10 mi) E earthquakes near Sabana Grande Municipio
Maricao Municipio, PR 21 km (13 mi) NE earthquakes near Maricao 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. 2.2 7 km WSW of La Playa, Puerto Rico
  2. 3.0 16 km WSW of Stella, Puerto Rico
  3. 2.9 2 km NNW of Boquerón, Puerto Rico
  4. 2.1 0 km NNW of Hormigueros, Puerto Rico
  5. 1.6 7 km W of La Parguera, Puerto Rico
  6. 2.9 4 km WSW of Las Marías, Puerto Rico
  7. 1.6 Mona Passage
  8. 2.1 7 km SE of Maricao, Puerto Rico
  9. 1.7 10 km ESE of Maricao, Puerto Rico
  10. 1.8 3 km NW of Fuig, Puerto Rico
  11. 2.0 4 km W of Palmarejo, Puerto Rico
  12. 2.4 5 km WNW of Aguada, Puerto Rico
  13. 2.1 2 km SE of Palmarejo, Puerto Rico
  14. 2.3 12 km WNW of Adjuntas, Puerto Rico
  15. 2.2 10 km SW of La Playa, 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.