QuakeIndex

Earthquake · reviewed by a seismologist

M 2.6md

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 2.6 earthquake was recorded 38 km (23 mi) north of Isabela, PR, at 11:58 pm AST on 19 December 2018 (03:58 UTC), 56 km deep.

USGS: 37 km N of Isabela, Puerto Rico

55 km (34 mi) NW of Arecibo, PR · 117 km (73 mi) WNW of San Juan, PR

11:58 pm AST, Dec 19, 2018 · · 56 km deep · released about 210 lb of TNT

Every earthquake near Isabela Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Isabela Municipio 40 kmAguadilla Municipio 40 kmQuebradillas Municipio 44 kmCamuy Municipio 49 kmMoca Municipio 51 kmAguada Municipio 52 kmHatillo Municipio 53 kmSan Sebastián Municipio 57 kmRincón 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
11:58 pm AST on 19 December 2018 ()
Where
38 km (23 mi) north of Isabela, PR · earthquakes near Isabela
Magnitude
M 2.6 (md)
Depth
56 km below the surface
Felt
no reports yet
Nearest
Isabela Municipio, 40 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2884 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 Isabela, 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 210 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 72,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 51,000× the energy of this one
  3. Around the size people start to feel M 3.0 4.6× the energy of this one
  4. This earthquake M 2.6 about 210 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 4.7 on 2017-07-17 — about 1,400 times the energy of this one.

Before 2016, the USGS record lists 21 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.7 45 km N of San Antonio, Puerto Rico · 9 km NNW of this epicentre
  2. 7.1 24 km NNW of San Antonio, Puerto Rico · 19 km SW of this epicentre
  3. 6.4 32 km NW of Aguadilla, Puerto Rico · 41 km SW of this epicentre
  4. 6.4 61 km N of Hatillo, Puerto Rico · 36 km NE of this epicentre
  5. 6.3 6 km WNW of Aguadilla, Puerto Rico · 46 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 18.8351, -67.0766. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Isabela Municipio, PR 40 km (25 mi) S earthquakes near Isabela Municipio
Aguadilla Municipio, PR 40 km (25 mi) S earthquakes near Aguadilla Municipio
Quebradillas Municipio, PR 44 km (27 mi) SSE earthquakes near Quebradillas Municipio
Camuy Municipio, PR 49 km (30 mi) SSE earthquakes near Camuy Municipio
Moca Municipio, PR 51 km (32 mi) S earthquakes near Moca Municipio
Aguada Municipio, PR 52 km (33 mi) SSW earthquakes near Aguada Municipio

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

Aftershocks so far

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

  1. 2.1 7 km NNE of Hatillo, Puerto Rico
  2. 2.7 Mona Passage
  3. 3.0 46 km NNW of San Antonio, Puerto Rico
  4. 3.1 48 km N of Hatillo, Puerto Rico
  5. 2.3 19 km NNE of Isabela, Puerto Rico
  6. 2.5 13 km N of Isabela, Puerto Rico
  7. 3.1 58 km N of San Antonio, Puerto Rico
  8. 3.1 77 km NNW of San Antonio, Puerto Rico
  9. 2.2 4 km ENE of Isabela, Puerto Rico
  10. 2.5 52 km NW of San Antonio, Puerto Rico
  11. 2.9 45 km NW of San Antonio, Puerto Rico
  12. 2.9 49 km N of Hatillo, Puerto Rico
  13. 2.4 13 km N of Carrizales, Puerto Rico
  14. 2.3 24 km NW of Rincón, Puerto Rico
  15. 3.0 46 km NNW 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.