QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8md

Earthquake near Mayagüez, PR

No earthquake was likely felt in Mayagüez in the 24 hours to 8:37 pm AST (00:37 UTC). The last one was M 2.9, 25 km (15 mi) SSE, at 3:17 am AST on 8 November 2026, estimated intensity II (weak) in town. Every earthquake near Mayagüez

This page: a magnitude 2.8 earthquake was recorded 9 km (6 mi) west of Mayagüez, PR, at 3:34 am AST on 29 July 2018 (07:34 UTC), 112 km deep.

USGS: 9 km W of Mayagüez, Puerto Rico

9 km (5 mi) W of Mayagüez, PR · 124 km (77 mi) W of San Juan, PR

3:34 am AST, Jul 29, 2018 · · 112 km deep · released about 430 lb of TNT

Every earthquake near Mayagüez Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Añasco Municipio 13 kmHormigueros Municipio 14 kmRincón Municipio 15 kmAguada Municipio 19 kmSan Germán Municipio 23 kmCabo Rojo Municipio 24 kmMoca Municipio 24 kmLas Marías Municipio 26 kmSan Sebastián Municipio 30 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
3:34 am AST on 29 July 2018 ()
Where
9 km (6 mi) west of Mayagüez, PR · earthquakes near Mayagüez
Magnitude
M 2.8 (md)
Depth
112 km below the surface
Felt
no reports yet
Nearest
Añasco Municipio, 13 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3028 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Mayagüez, 9 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: La Playa, Añasco, Las Marias, Stella, Hormigueros, Espino.

How big was it?

This earthquake released about 430 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 35,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 25,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.2× the energy of this one
  4. This earthquake M 2.8 about 430 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 200 times the energy of this one.

Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 32 km NW of Aguadilla, Puerto Rico · 48 km NNW of this epicentre
  2. 6.3 6 km WNW of Aguadilla, Puerto Rico · 26 km N of this epicentre
  3. 6.1 15 km WNW of San Antonio, Puerto Rico · 38 km N of this epicentre
  4. 6.1 18 km NNW of San Antonio, Puerto Rico · 48 km N of this epicentre
  5. 5.8 4 km E of Moca, Puerto Rico · 27 km NE 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 18.2095, -67.2245. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Añasco Municipio, PR 13 km (8 mi) NE earthquakes near Añasco Municipio
Hormigueros Municipio, PR 14 km (9 mi) SE earthquakes near Hormigueros Municipio
Rincón Municipio, PR 15 km (9 mi) N earthquakes near Rincón Municipio
Aguada Municipio, PR 19 km (12 mi) NNE earthquakes near Aguada Municipio
San Germán Municipio, PR 23 km (14 mi) ESE earthquakes near San Germán Municipio
Cabo Rojo Municipio, PR 24 km (15 mi) S earthquakes near Cabo Rojo Municipio

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

Aftershocks so far

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

  1. 1.9 4 km SE of Lajas, Puerto Rico
  2. 1.6 2 km SSW of Pole Ojea, Puerto Rico
  3. 2.1 3 km E of Hormigueros, Puerto Rico
  4. 2.5 4 km N of San Germán, Puerto Rico
  5. 2.4 24 km WSW of Stella, Puerto Rico
  6. 1.8 7 km W of Puerto Real, Puerto Rico
  7. 2.0 4 km WNW of Puerto Real, Puerto Rico
  8. 2.4 4 km S of Stella, Puerto Rico
  9. 2.2 9 km NNE of San Antonio, Puerto Rico
  10. 1.6 12 km S of La Parguera, Puerto Rico
  11. 1.7 2 km SE of Cabo Rojo, Puerto Rico
  12. 2.8 39 km W of Rincón, Puerto Rico
  13. 2.3 6 km SW of Las Marías, Puerto Rico
  14. 2.3 4 km NNE of La Parguera, Puerto Rico
  15. 2.5 37 km WNW of Rincón, 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.