QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Mayagüez, PR

No earthquake was likely felt in Mayagüez in the 24 hours to 7:53 pm AST (23:53 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 2.1 earthquake was recorded 4 km (3 mi) north-northwest of Mayagüez, PR, at 2:03 am AST on 9 September 2018 (06:03 UTC), 5.0 km deep.

USGS: 4 km NNW of Mayagüez, Puerto Rico

in Mayagüez, PR · 117 km (73 mi) W of San Juan, PR

2:03 am AST, Sep 9, 2018 · · 5.0 km deep · released about 46 lb of TNT

Every earthquake near Mayagüez Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Añasco Municipio 7 kmHormigueros Municipio 12 kmRincón Municipio 15 kmAguada Municipio 16 kmMoca Municipio 18 kmSan Germán Municipio 19 kmLas Marías Municipio 19 kmSan Sebastián Municipio 23 kmMaricao Municipio 25 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
2:03 am AST on 9 September 2018 ()
Where
4 km (3 mi) north-northwest of Mayagüez, PR · earthquakes near Mayagüez
Magnitude
M 2.1 (md)
Depth
5.0 km below the surface
Felt
no reports yet
Nearest
Añasco Municipio, 7 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2986 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 17 km (11 mi) from the epicentre. In Mayagüez, 4 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: Mayagüez 4 km, intensity II · Rincón 15 km, intensity II · Aguada 16 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 46 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 330,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 230,000× the energy of this one
  3. Around the size people start to feel M 3.0 21× the energy of this one
  4. This earthquake M 2.1 about 46 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 1,900 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 · 49 km NNW of this epicentre
  2. 6.3 6 km WNW of Aguadilla, Puerto Rico · 24 km NNW of this epicentre
  3. 6.1 15 km WNW of San Antonio, Puerto Rico · 36 km NNW of this epicentre
  4. 6.1 18 km NNW of San Antonio, Puerto Rico · 45 km N of this epicentre
  5. 5.8 4 km E of Moca, Puerto Rico · 21 km NNE 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 18.2341, -67.1616. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Añasco Municipio, PR 7 km (4 mi) NNE earthquakes near Añasco Municipio
Hormigueros Municipio, PR 12 km (7 mi) SSE earthquakes near Hormigueros Municipio
Rincón Municipio, PR 15 km (9 mi) NW earthquakes near Rincón Municipio
Aguada Municipio, PR 16 km (10 mi) N earthquakes near Aguada Municipio
Moca Municipio, PR 18 km (11 mi) NNE earthquakes near Moca Municipio
San Germán Municipio, PR 19 km (12 mi) SE earthquakes near San Germán Municipio

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

Aftershocks so far

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

  1. 2.1 2 km E of San Sebastián, Puerto Rico
  2. 1.9 4 km SW of Adjuntas, Puerto Rico
  3. 2.3 15 km WSW of Puerto Real, Puerto Rico
  4. 2.4 10 km NW of Puerto Real, Puerto Rico
  5. 2.1 5 km NW of Puerto Real, Puerto Rico
  6. 2.3 6 km W of Boquerón, Puerto Rico
  7. 2.2 27 km WNW of Aguadilla, Puerto Rico
  8. 2.4 22 km W of Pole Ojea, Puerto Rico
  9. 2.1 5 km SE of Lajas, Puerto Rico
  10. 2.5 7 km E of Mayagüez, Puerto Rico
  11. 1.9 8 km NW of Santo Domingo, Puerto Rico
  12. 1.8 4 km NNE of Yauco, Puerto Rico
  13. 1.7 6 km SW of Guánica, Puerto Rico
  14. 1.8 1 km W of Mayagüez, Puerto Rico
  15. 2.0 6 km ESE 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.