QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Sabana Grande, PR

No earthquake was likely felt in Sabana Grande in the 24 hours to 10:50 am AST (14:50 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 1.8 earthquake was recorded 3 km (2 mi) west-southwest of Sabana Grande, PR, at 7:48 am AST on 23 March 2018 (11:48 UTC), 42 km deep.

USGS: 3 km WSW of Sabana Grande, Puerto Rico

40 km (25 mi) WNW of Ponce, PR · 22 km (13 mi) SE of Mayagüez, PR

7:48 am AST, Mar 23, 2018 · · 42 km deep · released about 17 lb of TNT

Every earthquake near Sabana Grande Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Sabana Grande Municipio 5 kmSan Germán Municipio 6 kmLajas Municipio 11 kmMaricao Municipio 13 kmYauco Municipio 14 kmHormigueros Municipio 15 kmGuánica Municipio 15 kmLas Marías Municipio 18 kmCabo Rojo Municipio 22 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
7:48 am AST on 23 March 2018 ()
Where
3 km (2 mi) west-southwest of Sabana Grande, PR · earthquakes near Sabana Grande
Magnitude
M 1.8 (md)
Depth
42 km below the surface
Felt
no reports yet
Nearest
Sabana Grande Municipio, 5 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3155 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 Sabana Grande, 3 km away, the estimate is intensity I (not felt). 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: San Germán, Liborio Negron Torres, Lajas, Palmarejo, Sabana Eneas, Lluveras.

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

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 · 47 km NNW of this epicentre
  2. 5.8 4 km E of Moca, Puerto Rico · 38 km NNW of this epicentre
  3. 5.2 19 km SW of Stella, Puerto Rico · 42 km WNW of this epicentre
  4. 5.1 21 km SW of Stella, Puerto Rico · 42 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 18.0696, -66.9918. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sabana Grande Municipio, PR 5 km (3 mi) ENE earthquakes near Sabana Grande Municipio
San Germán Municipio, PR 6 km (4 mi) NW earthquakes near San Germán Municipio
Lajas Municipio, PR 11 km (7 mi) SSW earthquakes near Lajas Municipio
Maricao Municipio, PR 13 km (8 mi) NNE earthquakes near Maricao Municipio
Yauco Municipio, PR 14 km (9 mi) E earthquakes near Yauco Municipio
Hormigueros Municipio, PR 15 km (9 mi) WNW earthquakes near Hormigueros Municipio

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

Aftershocks so far

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

  1. 1.9 5 km ESE of Las Marías, Puerto Rico
  2. 1.5 5 km NNW of Yauco, Puerto Rico
  3. 2.4 2 km ESE of Las Marías, Puerto Rico
  4. 1.8 4 km E of Las Marías, Puerto Rico
  5. 2.0 4 km E of Las Marías, Puerto Rico
  6. 1.6 2 km NW of Maricao, Puerto Rico
  7. 1.8 6 km NW of Boquerón, Puerto Rico
  8. 1.9 6 km NE of Maricao, Puerto Rico
  9. 2.1 4 km NE of Maricao, Puerto Rico
  10. 2.3 4 km ESE of Las Marías, Puerto Rico
  11. 2.2 3 km ENE of Las Marías, Puerto Rico
  12. 1.7 4 km ESE of Boquerón, Puerto Rico
  13. 1.7 4 km SW of Palmarejo, Puerto Rico
  14. 2.1 4 km ESE of Las Marías, Puerto Rico
  15. 2.1 3 km E of Las Marías, 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.