QuakeIndex

Earthquake · reviewed by a seismologist

M 3.5md

Earthquake near Mayagüez, PR

No earthquake was likely felt in Mayagüez in the 24 hours to 4:39 pm AST (20:39 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 3.5 earthquake was recorded 50 km (31 mi) north of Mayagüez, PR, at 9:27 pm AST on 8 December 2023 (01:27 UTC), 80 km deep.

USGS: 19 km NNW of San Antonio, Puerto Rico

50 km (31 mi) N of Mayagüez, PR · 122 km (76 mi) WNW of San Juan, PR

9:27 pm AST, Dec 8, 2023 · · 80 km deep · released about 2.5 tons of TNT

Every earthquake near Mayagüez Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Aguadilla Municipio 19 kmIsabela Municipio 26 kmAguada Municipio 30 kmMoca Municipio 32 kmQuebradillas Municipio 34 kmRincón Municipio 34 kmAñasco Municipio 40 kmCamuy Municipio 41 kmSan Sebastián Municipio 42 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
9:27 pm AST on 8 December 2023 ()
Where
50 km (31 mi) north of Mayagüez, PR · earthquakes near Mayagüez
Magnitude
M 3.5 (md)
Depth
80 km below the surface
Felt
no reports yet
Nearest
Aguadilla Municipio, 19 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1005 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 it was probably too small to be felt, even directly above it. In Mayagüez, 50 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: Rafael Hernandez, Caban, Isabela, Aguadilla, Aceitunas, Mora.

How big was it?

This earthquake released about 2.5 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.5 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 68,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 3,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,100× the energy of this one
  4. This earthquake M 3.5 about 2.5 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 5.2× 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 6.0 on 2019-09-24 — about 6,000 times the energy of this one.

Before 2016, the USGS record lists 13 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.7 45 km N of San Antonio, Puerto Rico · 30 km NNE of this epicentre
  2. 7.1 24 km NNW of San Antonio, Puerto Rico · 6 km N of this epicentre
  3. 6.4 32 km NW of Aguadilla, Puerto Rico · 21 km W of this epicentre
  4. 6.3 6 km WNW of Aguadilla, Puerto Rico · 23 km S of this epicentre
  5. 6.1 15 km WNW of San Antonio, Puerto Rico · 11 km SSW 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 18.6440, -67.1910. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Aguadilla Municipio, PR 19 km (12 mi) SSE earthquakes near Aguadilla Municipio
Isabela Municipio, PR 26 km (16 mi) SE earthquakes near Isabela Municipio
Aguada Municipio, PR 30 km (19 mi) S earthquakes near Aguada Municipio
Moca Municipio, PR 32 km (20 mi) SSE earthquakes near Moca Municipio
Quebradillas Municipio, PR 34 km (21 mi) SE earthquakes near Quebradillas Municipio
Rincón Municipio, PR 34 km (21 mi) S earthquakes near Rincón Municipio

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

Aftershocks so far

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

  1. 3.1 3 km NNE of Mayagüez, Puerto Rico
  2. 3.2 46 km NW of San Antonio, Puerto Rico
  3. 3.3 61 km NW of San Antonio, Puerto Rico
  4. 3.2 12 km NW of San Antonio, Puerto Rico
  5. 3.0 48 km NW of San Antonio, Puerto Rico
  6. 3.1 11 km NNE of Carrizales, Puerto Rico
  7. 2.8 23 km WNW of Rincón, Puerto Rico
  8. 3.6 39 km NW of Rincón, Puerto Rico
  9. 2.7 17 km N of Hatillo, Puerto Rico
  10. 3.1 48 km NW of San Antonio, Puerto Rico
  11. 3.4 37 km NNW of San Antonio, Puerto Rico
  12. 3.0 40 km NNW of San Antonio, Puerto Rico
  13. 4.0 48 km NW of San Antonio, Puerto Rico
  14. 3.3 48 km NW of San Antonio, Puerto Rico
  15. 4.0 49 km NW of San Antonio, 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.