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 7:56 pm AST (23:56 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 48 km (30 mi) north-northeast of Isabela, PR, at 8:03 am AST on 5 July 2018 (12:03 UTC), 10 km deep.

USGS: 47 km NNE of Isabela, Puerto Rico

54 km (34 mi) NNW of Arecibo, PR · 105 km (65 mi) WNW of San Juan, PR

8:03 am AST, Jul 5, 2018 · · 10 km deep · released about 140 lb of TNT

Every earthquake near Isabela Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Isabela Municipio 49 kmQuebradillas Municipio 50 kmCamuy Municipio 52 kmHatillo Municipio 54 kmAguadilla Municipio 55 kmArecibo Municipio 59 kmBarceloneta Municipio 61 kmMoca Municipio 62 kmSan Sebastián Municipio 65 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
8:03 am AST on 5 July 2018 ()
Where
48 km (30 mi) north-northeast of Isabela, PR · earthquakes near Isabela
Magnitude
M 2.4 (md)
Depth
10 km below the surface
Felt
no reports yet
Nearest
Isabela Municipio, 49 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3051 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 19 km (12 mi) from the epicentre. In Isabela, 48 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 140 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 5.8 110,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 78,000× the energy of this one
  3. Around the size people start to feel M 3.0 6.9× the energy of this one
  4. This earthquake M 2.4 about 140 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 2,100 times the energy of this one.

Before 2016, the USGS record lists 18 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.7 45 km N of San Antonio, Puerto Rico · 23 km W of this epicentre
  2. 7.1 24 km NNW of San Antonio, Puerto Rico · 38 km SW of this epicentre
  3. 6.4 61 km N of Hatillo, Puerto Rico · 17 km NE of this epicentre
  4. 6.1 18 km NNW of San Antonio, Puerto Rico · 42 km SW of this epicentre
  5. 6.0 81 km N of Isabela, Puerto Rico · 35 km N 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 18.9140, -66.9028. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Isabela Municipio, PR 49 km (31 mi) SSW earthquakes near Isabela Municipio
Quebradillas Municipio, PR 50 km (31 mi) S earthquakes near Quebradillas Municipio
Camuy Municipio, PR 52 km (32 mi) S earthquakes near Camuy Municipio
Hatillo Municipio, PR 54 km (33 mi) SSE earthquakes near Hatillo Municipio
Aguadilla Municipio, PR 55 km (34 mi) SSW earthquakes near Aguadilla Municipio
Arecibo Municipio, PR 59 km (36 mi) SSE earthquakes near Arecibo Municipio

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

Aftershocks so far

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

  1. 2.5 19 km N of Arecibo, Puerto Rico
  2. 2.7 41 km NW of San Antonio, Puerto Rico
  3. 2.9 43 km N of Isabela, Puerto Rico
  4. 2.2 9 km NNE of San Antonio, Puerto Rico
  5. 2.5 23 km N of Carrizales, Puerto Rico
  6. 3.2 59 km N of San Antonio, Puerto Rico
  7. 2.8 56 km N of Hatillo, Puerto Rico
  8. 2.4 33 km NNW of Tierras Nuevas Poniente, Puerto Rico
  9. 2.8 32 km NNW of San Antonio, Puerto Rico
  10. 2.4 58 km N of Hatillo, Puerto Rico
  11. 2.2 44 km NNE of Carrizales, Puerto Rico
  12. 1.8 3 km NE of Hatillo, Puerto Rico
  13. 2.3 18 km NNE of Arecibo, Puerto Rico
  14. 2.5 9 km NNE of Isabela, Puerto Rico
  15. 2.5 12 km N of Hatillo, 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.