QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

Earthquake near Las Marias, PR

No earthquake was likely felt in Las Marias in the 24 hours to 8:02 pm AST (00:02 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 2.3 earthquake was recorded 11 km (7 mi) east-southeast of Las Marias, PR, at 9:36 pm AST on 7 July 2018 (01:36 UTC), 19 km deep.

USGS: 5 km WNW of Las Marías, Puerto Rico

13 km (8 mi) NE of Mayagüez, PR · 104 km (65 mi) W of San Juan, PR

9:36 pm AST, Jul 7, 2018 · · 19 km deep · released about 88 lb of TNT

Every earthquake near Las Marias Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Las Marías Municipio 8 kmAñasco Municipio 10 kmSan Sebastián Municipio 11 kmMoca Municipio 13 kmMaricao Municipio 15 kmHormigueros Municipio 17 kmSan Germán Municipio 18 kmLares Municipio 18 kmAguada Municipio 19 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
9:36 pm AST on 7 July 2018 ()
Where
11 km (7 mi) east-southeast of Las Marias, PR · earthquakes near Las Marias
Magnitude
M 2.3 (md)
Depth
19 km below the surface
Felt
no reports yet
Nearest
Las Marías Municipio, 8 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2967 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 6 km (4 mi) from the epicentre. In Las Marias, 11 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: Espino, San Sebastián, Añasco, Maricao, Mayagüez, Juncal.

How big was it?

This earthquake released about 88 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 170,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 120,000× the energy of this one
  3. Around the size people start to feel M 3.0 11× the energy of this one
  4. This earthquake M 2.3 about 88 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 since 2016 was M 4.3 on 2017-10-14 — about 970 times the energy of this one.

Before 2016, the USGS record lists 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.3 6 km WNW of Aguadilla, Puerto Rico · 27 km NW of this epicentre
  2. 6.1 15 km WNW of San Antonio, Puerto Rico · 37 km NNW of this epicentre
  3. 6.1 18 km NNW of San Antonio, Puerto Rico · 44 km NNW of this epicentre
  4. 5.8 4 km E of Moca, Puerto Rico · 15 km N of this epicentre
  5. 5.2 19 km SW of Stella, Puerto Rico · 36 km WSW 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 18.2668, -67.0425. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Las Marías Municipio, PR 8 km (5 mi) ESE earthquakes near Las Marías Municipio
Añasco Municipio, PR 10 km (6 mi) WNW earthquakes near Añasco Municipio
San Sebastián Municipio, PR 11 km (7 mi) NE earthquakes near San Sebastián Municipio
Moca Municipio, PR 13 km (8 mi) NNW earthquakes near Moca Municipio
Maricao Municipio, PR 15 km (10 mi) SE earthquakes near Maricao Municipio
Hormigueros Municipio, PR 17 km (10 mi) SSW earthquakes near Hormigueros Municipio

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

Aftershocks so far

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

  1. 2.2 2 km SSW of Tallaboa, Puerto Rico
  2. 3.2 Puerto Rico region
  3. 2.4 5 km NW of Rincón, Puerto Rico
  4. 1.7 4 km SSW of Pole Ojea, Puerto Rico
  5. 2.0 4 km SSW of Pole Ojea, Puerto Rico
  6. 2.1 2 km SSE of La Parguera, Puerto Rico
  7. 2.5 5 km W of Hormigueros, Puerto Rico
  8. 2.5 11 km N of Carrizales, Puerto Rico
  9. 2.2 15 km NNE of Isabela, Puerto Rico
  10. 2.6 7 km SSW of La Playa, Puerto Rico
  11. 2.0 12 km SW of Pole Ojea, Puerto Rico
  12. 2.5 3 km ENE of Isabela, Puerto Rico
  13. 2.1 0 km WSW of Puerto Real, Puerto Rico
  14. 1.6 9 km S of La Parguera, Puerto Rico
  15. 2.1 3 km WNW of Maricao, 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.