QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4md

Earthquake near Isabela, PR

No earthquake was likely felt in Isabela in the 24 hours to 3:27 pm AST (19:27 UTC). The last one was M 3.4, 31 km (19 mi) N, at 9:00 pm AST on 27 October 2026, estimated intensity II (weak) in town. Every earthquake near Isabela

This page: a magnitude 2.4 earthquake was recorded 16 km (10 mi) north of Isabela, PR, at 2:25 am AST on 26 December 2018 (06:25 UTC), 20 km deep.

USGS: 16 km N of Isabela, Puerto Rico

39 km (24 mi) WNW of Arecibo, PR · 107 km (66 mi) WNW of San Juan, PR

2:25 am AST, Dec 26, 2018 · · 20 km deep · released about 100 lb of TNT

Every earthquake near Isabela Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Isabela Municipio 18 kmAguadilla Municipio 21 kmQuebradillas Municipio 23 kmCamuy Municipio 29 kmMoca Municipio 30 kmAguada Municipio 34 kmHatillo Municipio 34 kmSan Sebastián Municipio 36 kmRincón Municipio 41 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
2:25 am AST on 26 December 2018 ()
Where
16 km (10 mi) north of Isabela, PR · earthquakes near Isabela
Magnitude
M 2.4 (md)
Depth
20 km below the surface
Felt
no reports yet
Nearest
Isabela Municipio, 18 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2877 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 4 km (2 mi) from the epicentre. In Isabela, 16 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, Mora, Quebradillas, Aceitunas, Caban, Cacao.

How big was it?

This earthquake released about 100 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 150,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 110,000× the energy of this one
  3. Around the size people start to feel M 3.0 9.4× the energy of this one
  4. This earthquake M 2.4 about 100 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 4.3 on 2017-10-14 — about 840 times the energy of this one.

Before 2016, the USGS record lists 14 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.7 45 km N of San Antonio, Puerto Rico · 30 km NNW of this epicentre
  2. 7.1 24 km NNW of San Antonio, Puerto Rico · 17 km WNW of this epicentre
  3. 6.4 32 km NW of Aguadilla, Puerto Rico · 36 km W of this epicentre
  4. 6.3 6 km WNW of Aguadilla, Puerto Rico · 29 km SW of this epicentre
  5. 6.1 15 km WNW of San Antonio, Puerto Rico · 23 km WSW 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 18.6450, -67.0420. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Isabela Municipio, PR 18 km (11 mi) S earthquakes near Isabela Municipio
Aguadilla Municipio, PR 21 km (13 mi) SSW earthquakes near Aguadilla Municipio
Quebradillas Municipio, PR 23 km (14 mi) SSE earthquakes near Quebradillas Municipio
Camuy Municipio, PR 29 km (18 mi) SE earthquakes near Camuy Municipio
Moca Municipio, PR 30 km (19 mi) S earthquakes near Moca Municipio
Aguada Municipio, PR 34 km (21 mi) SSW earthquakes near Aguada Municipio

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

Aftershocks so far

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

  1. 2.9 8 km NNE of Animas, Puerto Rico
  2. 2.4 15 km NNE of Isabela, Puerto Rico
  3. 2.1 7 km NNE of Hatillo, Puerto Rico
  4. 2.7 Mona Passage
  5. 2.0 18 km N of Garrochales, Puerto Rico
  6. 3.0 46 km NNW of San Antonio, Puerto Rico
  7. 3.1 48 km N of Hatillo, Puerto Rico
  8. 2.3 19 km NNE of Isabela, Puerto Rico
  9. 2.5 13 km N of Isabela, Puerto Rico
  10. 1.8 3 km W of Rafael Capo, Puerto Rico
  11. 3.1 58 km N of San Antonio, Puerto Rico
  12. 2.2 4 km ENE of Isabela, Puerto Rico
  13. 2.5 52 km NW of San Antonio, Puerto Rico
  14. 2.2 34 km NW of Rincón, Puerto Rico
  15. 2.9 45 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.