QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

Earthquake near Las Marias, PR

No earthquake was likely felt in Las Marias in the 24 hours to 7:54 pm AST (23:54 UTC). The last one was M 3.5, 12 km (8 mi) NNE, at 12:03 am AST on 6 November 2026, estimated intensity II (weak) in town. Every earthquake near Las Marias

This page: a magnitude 1.9 earthquake was recorded 23 km (14 mi) east-southeast of Las Marias, PR, at 1:21 am AST on 8 April 2018 (05:21 UTC), 8.0 km deep.

USGS: 5 km ESE of Las Marías, Puerto Rico

94 km (58 mi) W of San Juan, PR · 22 km (14 mi) ENE of Mayagüez, PR

1:21 am AST, Apr 8, 2018 · · 8.0 km deep · released about 19 lb of TNT

Every earthquake near Las Marias Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Las Marías Municipio 4 kmMaricao Municipio 7 kmLares Municipio 8 kmSan Sebastián Municipio 11 kmSabana Grande Municipio 17 kmSan Germán Municipio 18 kmYauco Municipio 19 kmAdjuntas Municipio 20 kmAñasco 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
1:21 am AST on 8 April 2018 ()
Where
23 km (14 mi) east-southeast of Las Marias, PR · earthquakes near Las Marias
Magnitude
M 1.9 (md)
Depth
8.0 km below the surface
Felt
no reports yet
Nearest
Las Marías Municipio, 4 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3140 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 12 km (7 mi) from the epicentre. In Las Marias, 23 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: Lares 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 19 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 810,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 580,000× the energy of this one
  3. Around the size people start to feel M 3.0 51× the energy of this one
  4. This earthquake M 1.9 about 19 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 · 37 km NW of this epicentre
  2. 6.1 15 km WNW of San Antonio, Puerto Rico · 46 km NW of this epicentre
  3. 5.8 4 km E of Moca, Puerto Rico · 23 km NW of this epicentre
  4. 5.2 19 km SW of Stella, Puerto Rico · 46 km W of this epicentre
  5. 5.1 21 km SW of Stella, Puerto Rico · 46 km W 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 18.2398, -66.9385. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Las Marías Municipio, PR 4 km (3 mi) WSW earthquakes near Las Marías Municipio
Maricao Municipio, PR 7 km (5 mi) S earthquakes near Maricao Municipio
Lares Municipio, PR 8 km (5 mi) ENE earthquakes near Lares Municipio
San Sebastián Municipio, PR 11 km (7 mi) NNW earthquakes near San Sebastián Municipio
Sabana Grande Municipio, PR 17 km (11 mi) S earthquakes near Sabana Grande Municipio
San Germán Municipio, PR 18 km (11 mi) SW earthquakes near San Germán Municipio

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

Aftershocks so far

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

  1. 2.4 5 km SE of Ponce, Puerto Rico
  2. 2.1 5 km SE of Ponce, Puerto Rico
  3. 1.9 4 km ESE of Ponce, Puerto Rico
  4. 1.9 4 km SW of Coto Laurel, Puerto Rico
  5. 2.0 2 km SE of Ponce, Puerto Rico
  6. 2.3 4 km SE of Ponce, Puerto Rico
  7. 2.1 6 km SSW of La Playa, Puerto Rico
  8. 2.2 6 km SSW of La Playa, Puerto Rico
  9. 2.8 16 km NNE of Carrizales, Puerto Rico
  10. 2.0 2 km NE of Puerto Real, Puerto Rico
  11. 2.0 11 km NW of Puerto Real, Puerto Rico
  12. 1.8 6 km WSW of Guánica, Puerto Rico
  13. 1.6 0 km SE of La Parguera, Puerto Rico
  14. 2.3 4 km SW of Maricao, Puerto Rico
  15. 2.4 20 km N of Hatillo, 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.