QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

Earthquake near Maricao, PR

No earthquake was likely felt in Maricao in the 24 hours to 8:04 pm AST (00:04 UTC). The last one was M 3.0, 33 km (20 mi) SSE, at 3:45 am AST on 8 November 2026, estimated intensity II (weak) in town. Every earthquake near Maricao

This page: a magnitude 1.6 earthquake was recorded 7 km (4 mi) west-northwest of Maricao, PR, at 8:43 pm AST on 20 June 2018 (00:43 UTC), 24 km deep.

USGS: 7 km WNW of Maricao, Puerto Rico

10 km (6 mi) E of Mayagüez, PR · 106 km (66 mi) WSW of San Juan, PR

8:43 pm AST, Jun 20, 2018 · · 24 km deep · released about 9 lb of TNT

Every earthquake near Maricao Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Las Marías Municipio 8 kmSan Germán Municipio 10 kmHormigueros Municipio 11 kmMaricao Municipio 12 kmAñasco Municipio 13 kmSabana Grande Municipio 16 kmSan Sebastián Municipio 17 kmMoca Municipio 20 kmLares Municipio 20 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
8:43 pm AST on 20 June 2018 ()
Where
7 km (4 mi) west-northwest of Maricao, PR · earthquakes near Maricao
Magnitude
M 1.6 (md)
Depth
24 km below the surface
Felt
no reports yet
Nearest
Las Marías Municipio, 8 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3066 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 Maricao, 7 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: Mayagüez, Hormigueros, Espino, San Germán, Sabana Eneas, Añasco.

How big was it?

This earthquake released about 9 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,200,000× the energy of this one
  3. Around the size people start to feel M 3.0 110× the energy of this one
  4. This earthquake M 1.6 about 9 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 9,400 times the energy of this one.

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 · 32 km NW of this epicentre
  2. 6.1 15 km WNW of San Antonio, Puerto Rico · 44 km NNW of this epicentre
  3. 5.8 4 km E of Moca, Puerto Rico · 23 km N of this epicentre
  4. 5.2 19 km SW of Stella, Puerto Rico · 35 km W of this epicentre
  5. 5.1 21 km SW of Stella, Puerto Rico · 35 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 18.1991, -67.0435. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Las Marías Municipio, PR 8 km (5 mi) ENE earthquakes near Las Marías Municipio
San Germán Municipio, PR 10 km (6 mi) S earthquakes near San Germán Municipio
Hormigueros Municipio, PR 11 km (7 mi) SW earthquakes near Hormigueros Municipio
Maricao Municipio, PR 12 km (7 mi) ESE earthquakes near Maricao Municipio
Añasco Municipio, PR 13 km (8 mi) NW earthquakes near Añasco Municipio
Sabana Grande Municipio, PR 16 km (10 mi) SE earthquakes near Sabana Grande Municipio

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

Aftershocks so far

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

  1. 1.9 17 km SSE of Guánica, Puerto Rico
  2. 2.0 20 km SW of Stella, Puerto Rico
  3. 2.1 3 km E of Pole Ojea, Puerto Rico
  4. 1.8 19 km S of Guánica, Puerto Rico
  5. 2.7 6 km E of Espino, Puerto Rico
  6. 2.3 5 km WNW of Las Marías, Puerto Rico
  7. 2.3 5 km E of Espino, Puerto Rico
  8. 2.0 6 km ENE of Espino, Puerto Rico
  9. 1.9 8 km WSW of Puerto Real, Puerto Rico
  10. 1.9 12 km SSE of Maria Antonia, Puerto Rico
  11. 2.0 12 km NW of Puerto Real, Puerto Rico
  12. 2.3 33 km SW of Stella, Puerto Rico
  13. 2.1 1 km W of Puerto Real, Puerto Rico
  14. 2.5 19 km SW of Stella, Puerto Rico
  15. 2.5 22 km W of Pole Ojea, 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.