QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0md

53 km NNE of Isabela, Puerto Rico

Yes. A magnitude 3.0 earthquake was recorded 53 km NNE of Isabela, Puerto Rico, 59 km (37 mi) NNW of Arecibo, PR, at 7:06 am AST on 4 April 2018 (11:06 UTC), 36 km deep.

59 km (37 mi) NNW of Arecibo, PR · 107 km (67 mi) NW of San Juan, PR

· 36 km deep · released about 950 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Isabela Municipio 56 kmQuebradillas Municipio 56 kmCamuy Municipio 58 kmHatillo Municipio 59 kmAguadilla Municipio 61 kmArecibo Municipio 64 kmBarceloneta Municipio 66 kmMoca Municipio 69 kmSan Sebastián Municipio 71 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
Magnitude
M 3.0 (md)
Depth
36 km below the surface
Felt
no reports yet
Nearest
Isabela Municipio, 56 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3143 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, people at rest would likely notice it out to about 8 km (5 mi) from the epicentre. 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 950 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 350,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 16,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 11,000× the energy of this one
  4. This earthquake M 3.0 about 950 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 310 times the energy of this one.

Before 2016, the USGS record lists 17 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.7 45 km N of San Antonio, Puerto Rico · 25 km WSW of this epicentre
  2. 7.1 24 km NNW of San Antonio, Puerto Rico · 43 km SW of this epicentre
  3. 6.4 61 km N of Hatillo, Puerto Rico · 12 km NE of this epicentre
  4. 6.1 18 km NNW of San Antonio, Puerto Rico · 48 km SW of this epicentre
  5. 6.0 81 km N of Isabela, Puerto Rico · 29 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 18.9691, -66.8896. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Isabela Municipio, PR 56 km (34 mi) SSW earthquakes near Isabela Municipio
Quebradillas Municipio, PR 56 km (35 mi) S earthquakes near Quebradillas Municipio
Camuy Municipio, PR 58 km (36 mi) S earthquakes near Camuy Municipio
Hatillo Municipio, PR 59 km (37 mi) S earthquakes near Hatillo Municipio
Aguadilla Municipio, PR 61 km (38 mi) SSW earthquakes near Aguadilla Municipio
Arecibo Municipio, PR 64 km (40 mi) SSE earthquakes near Arecibo 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. 1.6 36 km N of San Antonio, Puerto Rico
  2. 2.8 Puerto Rico region
  3. 2.9 52 km N of Hatillo, Puerto Rico
  4. 2.8 Puerto Rico region
  5. 2.8 62 km N of Hatillo, Puerto Rico
  6. 2.5 82 km N of Tierras Nuevas Poniente, Puerto Rico
  7. 2.3 18 km NNE of Hatillo, Puerto Rico
  8. 2.6 49 km N of Arecibo, Puerto Rico
  9. 3.0 66 km N of Hatillo, Puerto Rico
  10. 2.3 42 km NNW of San Antonio, Puerto Rico
  11. 2.5 55 km N of Carrizales, Puerto Rico
  12. 3.3 73 km NNW of San Antonio, Puerto Rico
  13. 3.2 Puerto Rico region
  14. 3.1 Mona Passage
  15. 2.9 48 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.