QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Sabana Grande, PR

No earthquake was likely felt in Sabana Grande in the 24 hours to 10:10 am AST (14:10 UTC). The last one was M 3.0, 22 km (13 mi) SSE, at 3:45 am AST on 8 November 2026, estimated intensity II (weak) in town. Every earthquake near Sabana Grande

This page: a magnitude 1.7 earthquake was recorded 4 km (2 mi) southeast of Sabana Grande, PR, at 12:18 am AST on 31 August 2023 (04:18 UTC), 7.7 km deep. 1 person has reported feeling it to USGS.

USGS: Puerto Rico region

33 km (21 mi) W of Ponce, PR · 27 km (17 mi) SE of Mayagüez, PR

12:18 am AST, Aug 31, 2023 · · 7.7 km deep · released about 11 lb of TNT

Every earthquake near Sabana Grande Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Sabana Grande Municipio 3 kmYauco Municipio 9 kmSan Germán Municipio 12 kmGuánica Municipio 12 kmMaricao Municipio 13 kmLajas Municipio 14 kmGuayanilla Municipio 16 kmLas Marías Municipio 19 kmHormigueros Municipio 21 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
12:18 am AST on 31 August 2023 ()
Where
4 km (2 mi) southeast of Sabana Grande, PR · earthquakes near Sabana Grande
Magnitude
M 1.7 (md)
Depth
7.7 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Sabana Grande Municipio, 3 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1168 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 10 km (6 mi) from the epicentre. In Sabana Grande, 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: Yauco 9 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 11 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 1,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 930,000× the energy of this one
  3. Around the size people start to feel M 3.0 83× the energy of this one
  4. This earthquake M 1.7 about 11 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 in our catalogue was M 6.4 on 2020-01-07 — about 10,000,000 times the energy of this one.

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 18.0582, -66.9343. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sabana Grande Municipio, PR 3 km (2 mi) NNW earthquakes near Sabana Grande Municipio
Yauco Municipio, PR 9 km (5 mi) ENE earthquakes near Yauco Municipio
San Germán Municipio, PR 12 km (8 mi) WNW earthquakes near San Germán Municipio
Guánica Municipio, PR 12 km (8 mi) S earthquakes near Guánica Municipio
Maricao Municipio, PR 13 km (8 mi) N earthquakes near Maricao Municipio
Lajas Municipio, PR 14 km (9 mi) SW earthquakes near Lajas Municipio

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

Aftershocks so far

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

  1. 2.4 1 km N of Indios, Puerto Rico
  2. 2.5 1 km WNW of Indios, Puerto Rico
  3. 2.3 2 km SW of Tallaboa, Puerto Rico
  4. 2.9 0 km SSW of Guayanilla, Puerto Rico
  5. 3.0 Puerto Rico region
  6. 2.4 5 km WSW of Maricao, Puerto Rico
  7. 2.2 1 km W of Fuig, Puerto Rico
  8. 2.8 2 km WSW of Guánica, Puerto Rico
  9. 2.5 4 km SW of Guánica, Puerto Rico
  10. 2.7 Puerto Rico region
  11. 2.2 0 km W of Gu?nica, Puerto Rico
  12. 2.7 0 km SE of Guayanilla, Puerto Rico
  13. 2.4 2 km NW of Tallaboa, Puerto Rico
  14. 2.2 2 km ESE of Maria Antonia, Puerto Rico
  15. 3.0 2 km SW of Guánica, 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.