QuakeIndex

Earthquake · reviewed by a seismologist

M 4.2md

Earthquake near Mayagüez, PR

No earthquake was likely felt in Mayagüez in the 24 hours to 4:28 am AST (08:28 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 4.2 earthquake was recorded 29 km (18 mi) south-southeast of Mayagüez, PR, at 8:44 am AST on 3 July 2023 (12:44 UTC), 7.0 km deep. 29 people have reported feeling it to USGS.

USGS: Puerto Rico region

29 km (18 mi) SSE of Mayagüez, PR · 119 km (74 mi) WSW of San Juan, PR

8:44 am AST, Jul 3, 2023 · · 7.0 km deep · released about 28 tons of TNT

Every earthquake near Mayagüez Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lajas Municipio 6 kmCabo Rojo Municipio 12 kmGuánica Municipio 17 kmSan Germán Municipio 18 kmSabana Grande Municipio 21 kmHormigueros Municipio 21 kmYauco Municipio 28 kmMaricao Municipio 30 kmGuayanilla Municipio 31 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
8:44 am AST on 3 July 2023 ()
Where
29 km (18 mi) south-southeast of Mayagüez, PR · earthquakes near Mayagüez
Magnitude
M 4.2 (md)
Depth
7.0 km below the surface
Felt
29 reports · strongest reported intensity IV
Measured shaking
intensity III (ShakeMap)
USGS impact alert
green
Nearest
Lajas Municipio, 6 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1158 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth, people at rest would likely notice it out to about 111 km (69 mi) from the epicentre. In Mayagüez, 29 km away, the estimate is intensity III (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: Pole Ojea 11 km, intensity IV · San Germán 15 km, intensity IV · Puerto Real 18 km, intensity III · Yauco 26 km, intensity III · Mayagüez 29 km, intensity III · Guayanilla 32 km, intensity III · Magas Arriba 34 km, intensity III · Tallaboa 39 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 28 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 6,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 270× the energy of this one
  3. Magna, Utah 2020 M 5.7 190× the energy of this one
  4. This earthquake M 4.2 about 28 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 59× 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 in our catalogue was M 6.4 on 2020-01-07 — about 2,100 times the energy of this one.

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 17.9478, -67.0815. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lajas Municipio, PR 6 km (3 mi) NE earthquakes near Lajas Municipio
Cabo Rojo Municipio, PR 12 km (7 mi) WNW earthquakes near Cabo Rojo Municipio
Guánica Municipio, PR 17 km (10 mi) E earthquakes near Guánica Municipio
San Germán Municipio, PR 18 km (11 mi) NNE earthquakes near San Germán Municipio
Sabana Grande Municipio, PR 21 km (13 mi) NE earthquakes near Sabana Grande Municipio
Hormigueros Municipio, PR 21 km (13 mi) N earthquakes near Hormigueros Municipio

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

Aftershocks so far

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

  1. 2.9 0 km NE of Magas Arriba, Puerto Rico
  2. 2.4 0 km NE of Guayanilla, Puerto Rico
  3. 2.6 Puerto Rico region
  4. 2.7 3 km NW of La Parguera, Puerto Rico
  5. 2.9 6 km SW of Guánica, Puerto Rico
  6. 2.5 1 km WSW of Fuig, Puerto Rico
  7. 2.4 6 km SSW of Indios, Puerto Rico
  8. 2.0 1 km S of Yauco, Puerto Rico
  9. 3.0 Puerto Rico region
  10. 2.1 3 km SW of Indios, Puerto Rico
  11. 2.1 Puerto Rico region
  12. 2.3 3 km S of Las Mar?as, Puerto Rico
  13. 2.3 4 km SSW of Indios, Puerto Rico
  14. 2.1 4 km SW of La Parguera, Puerto Rico
  15. 2.0 1 km N of Yauco, 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.