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 12:49 pm AST (16:49 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 6 km (4 mi) east of Mayagüez, PR, at 8:41 pm AST on 14 August 2021 (00:41 UTC), 18 km deep.

USGS: 6 km E of Mayagüez, Puerto Rico

7 km (4 mi) E of Mayagüez, PR · 110 km (68 mi) WSW of San Juan, PR

8:41 pm AST, Aug 14, 2021 · · 18 km deep · released about 47 lb of TNT

Every earthquake near Mayagüez Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Hormigueros Municipio 8 kmSan Germán Municipio 11 kmLas Marías Municipio 11 kmAñasco Municipio 11 kmMaricao Municipio 15 kmSabana Grande Municipio 19 kmSan Sebastián Municipio 19 kmMoca Municipio 20 kmAguada Municipio 23 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
8:41 pm AST on 14 August 2021 ()
Where
6 km (4 mi) east of Mayagüez, PR · earthquakes near Mayagüez
Magnitude
M 2.1 (md)
Depth
18 km below the surface
Felt
no reports yet
Nearest
Hormigueros Municipio, 8 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1915 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 Mayagüez, 6 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: Hormigueros, Espino, Maricao, Añasco, Sabana Eneas, Monte Grande.

How big was it?

This earthquake released about 47 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 5.8 320,000× 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 20× the energy of this one
  4. This earthquake M 2.1 about 47 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 6.4 on 2020-01-07 — about 2,500,000 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 · 31 km NNW of this epicentre
  2. 6.1 15 km WNW of San Antonio, Puerto Rico · 43 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 · 31 km W of this epicentre
  5. 5.1 21 km SW of Stella, Puerto Rico · 31 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 18.1968, -67.0800. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Hormigueros Municipio, PR 8 km (5 mi) SSW earthquakes near Hormigueros Municipio
San Germán Municipio, PR 11 km (7 mi) SSE earthquakes near San Germán Municipio
Las Marías Municipio, PR 11 km (7 mi) ENE earthquakes near Las Marías Municipio
Añasco Municipio, PR 11 km (7 mi) NNW earthquakes near Añasco Municipio
Maricao Municipio, PR 15 km (10 mi) E earthquakes near Maricao Municipio
Sabana Grande Municipio, PR 19 km (12 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

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

  1. 3.6 12 km S of Guánica, Puerto Rico
  2. 2.3 4 km SW of Indios, Puerto Rico
  3. 3.0 10 km SSE of Maria Antonia, Puerto Rico
  4. 2.5 3 km SSE of Maria Antonia, Puerto Rico
  5. 2.9 3 km SE of La Parguera, Puerto Rico
  6. 2.5 6 km SE of Pole Ojea, Puerto Rico
  7. 3.3 4 km SE of La Parguera, Puerto Rico
  8. 2.5 4 km SE of La Parguera, Puerto Rico
  9. 2.7 15 km SSE of Guánica, Puerto Rico
  10. 3.0 5 km SSE of Guánica, Puerto Rico
  11. 2.0 3 km SE of Maria Antonia, Puerto Rico
  12. 3.4 4 km SE of La Parguera, Puerto Rico
  13. 2.8 5 km S of Indios, Puerto Rico
  14. 2.6 12 km SSE of Maria Antonia, Puerto Rico
  15. 2.8 5 km WSW of Fuig, 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.