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 5:21 pm AST (21:21 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 38 km (24 mi) west of Mayagüez, PR, at 1:19 am AST on 30 March 2021 (05:19 UTC), 7.0 km deep.

USGS: 31 km WSW of Stella, Puerto Rico

94 km (58 mi) WNW of Ponce, PR · 38 km (23 mi) W of Mayagüez, PR

1:19 am AST, Mar 30, 2021 · · 7.0 km deep · released about 420 lb of TNT

Every earthquake near Mayagüez Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Rincón Municipio 32 kmCabo Rojo Municipio 38 kmAguada Municipio 40 kmHormigueros Municipio 40 kmAñasco Municipio 41 kmMayagüez Municipio 42 kmSan Germán Municipio 49 kmMoca Municipio 50 kmAguadilla Municipio 51 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
1:19 am AST on 30 March 2021 ()
Where
38 km (24 mi) west of Mayagüez, PR · earthquakes near Mayagüez
Magnitude
M 2.8 (md)
Depth
7.0 km below the surface
Felt
no reports yet
Nearest
Rincón Municipio, 32 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2053 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, people at rest would likely notice it out to about 25 km (16 mi) from the epicentre. In Mayagüez, 38 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.

How big was it?

This earthquake released about 420 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 36,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 26,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.3× the energy of this one
  4. This earthquake M 2.8 about 420 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 4.4 on 2017-10-01 — about 290 times the energy of this one.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

  1. 6.3 6 km WNW of Aguadilla, Puerto Rico · 42 km NE of this epicentre
  2. 5.2 19 km SW of Stella, Puerto Rico · 14 km E of this epicentre
  3. 5.1 21 km SW of Stella, Puerto Rico · 13 km E 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 18.1690, -67.4963. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Rincón Municipio, PR 32 km (20 mi) NE earthquakes near Rincón Municipio
Cabo Rojo Municipio, PR 38 km (24 mi) ESE earthquakes near Cabo Rojo Municipio
Aguada Municipio, PR 40 km (25 mi) NE earthquakes near Aguada Municipio
Hormigueros Municipio, PR 40 km (25 mi) E earthquakes near Hormigueros Municipio
Añasco Municipio, PR 41 km (25 mi) ENE earthquakes near Añasco Municipio
Mayagüez Municipio, PR 42 km (26 mi) WSW earthquakes near Mayagüez Municipio

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

Aftershocks so far

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

  1. 2.8 34 km WNW of Rincón, Puerto Rico
  2. 2.5 3 km E of Pole Ojea, Puerto Rico
  3. 2.4 3 km ENE of Pole Ojea, Puerto Rico
  4. 2.0 2 km NNE of Rincón, Puerto Rico
  5. 3.2 59 km W of Stella, Puerto Rico
  6. 1.8 4 km SSW of Palmarejo, Puerto Rico
  7. 2.5 16 km NW of Puerto Real, Puerto Rico
  8. 2.5 3 km NNW of La Parguera, Puerto Rico
  9. 3.2 38 km W of Rincón, Puerto Rico
  10. 2.6 13 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.