QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1md

Earthquake near Mayagüez, PR

No earthquake was likely felt in Mayagüez in the 24 hours to 4:14 am AST (08:14 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 3.1 earthquake was recorded 43 km (27 mi) west-southwest of Mayagüez, PR, at 9:08 pm AST on 21 March 2023 (01:08 UTC), 41 km deep.

USGS: 35 km W of Puerto Real, Puerto Rico

95 km (59 mi) W of Ponce, PR · 43 km (27 mi) WSW of Mayagüez, PR

9:08 pm AST, Mar 21, 2023 · · 41 km deep · released about 1,500 lb of TNT

Every earthquake near Mayagüez Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Cabo Rojo Municipio 37 kmMayagüez Municipio 39 kmRincón Municipio 42 kmHormigueros Municipio 43 kmAñasco Municipio 48 kmAguada Municipio 49 kmSan Germán Municipio 51 kmLajas Municipio 52 kmMoca Municipio 58 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
9:08 pm AST on 21 March 2023 ()
Where
43 km (27 mi) west-southwest of Mayagüez, PR · earthquakes near Mayagüez
Magnitude
M 3.1 (md)
Depth
41 km below the surface
Felt
no reports yet
Nearest
Cabo Rojo Municipio, 37 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1331 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 15 km (9 mi) from the epicentre. In Mayagüez, 43 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 1,500 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 220,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 9,800× the energy of this one
  3. Magna, Utah 2020 M 5.7 6,900× the energy of this one
  4. This earthquake M 3.1 about 1,500 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.6× more

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 4.5 on 2021-07-18 — about 95 times the energy of this one.

Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:

  1. 5.2 19 km SW of Stella, Puerto Rico · 21 km NE of this epicentre
  2. 5.1 21 km SW of Stella, Puerto Rico · 20 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 18.0645, -67.5192. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Cabo Rojo Municipio, PR 37 km (23 mi) ESE earthquakes near Cabo Rojo Municipio
Mayagüez Municipio, PR 39 km (24 mi) W earthquakes near Mayagüez Municipio
Rincón Municipio, PR 42 km (26 mi) NE earthquakes near Rincón Municipio
Hormigueros Municipio, PR 43 km (27 mi) E earthquakes near Hormigueros Municipio
Añasco Municipio, PR 48 km (30 mi) ENE earthquakes near Añasco Municipio
Aguada Municipio, PR 49 km (31 mi) NE earthquakes near Aguada Municipio

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

Aftershocks so far

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

  1. 2.8 23 km NW of Rinc?n, Puerto Rico
  2. 2.9 16 km W of Pole Ojea, Puerto Rico
  3. 2.5 10 km W of Stella, Puerto Rico
  4. 1.7 0 km N of Sabana Eneas, Puerto Rico
  5. 2.7 24 km WNW of Rincón, Puerto Rico
  6. 3.1 19 km SW of Stella, Puerto Rico
  7. 2.5 3 km E of Stella, Puerto Rico
  8. 1.8 0 km S of Palmarejo, Puerto Rico
  9. 2.4 0 km NNE of Palmarejo, Puerto Rico
  10. 3.4 16 km WNW of Rincón, Puerto Rico
  11. 2.3 5 km ESE of Pole Ojea, Puerto Rico
  12. 2.3 6 km SE of Boquerón, Puerto Rico
  13. 3.4 68 km SE of Punta Cana, Dominican Republic
  14. 2.4 Mona Passage
  15. 2.7 3 km SE of Palmarejo, 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.