QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1md

Earthquake near Arecibo, PR

No earthquake was likely felt in Arecibo in the 24 hours to 11:27 am AST (15:27 UTC). The last one was M 3.4, 49 km (31 mi) NW, at 9:00 pm AST on 27 October 2026, estimated intensity II (weak) in town. Every earthquake near Arecibo

This page: a magnitude 3.1 earthquake was recorded 23 km (14 mi) north of Arecibo, PR, at 6:44 pm AST on 1 April 2018 (22:44 UTC), 22 km deep.

USGS: 22 km N of Arecibo, Puerto Rico

74 km (46 mi) WNW of San Juan, PR · 25 km (16 mi) N of Arecibo, PR

6:44 pm AST, Apr 1, 2018 · · 22 km deep · released about 1,300 lb of TNT

Every earthquake near Arecibo Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Arecibo Municipio 27 kmBarceloneta Municipio 28 kmHatillo Municipio 28 kmCamuy Municipio 31 kmQuebradillas Municipio 33 kmManatí Municipio 34 kmFlorida Municipio 37 kmIsabela Municipio 39 kmVega Baja 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
6:44 pm AST on 1 April 2018 ()
Where
23 km (14 mi) north of Arecibo, PR · earthquakes near Arecibo
Magnitude
M 3.1 (md)
Depth
22 km below the surface
Felt
no reports yet
Nearest
Arecibo Municipio, 27 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3064 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 35 km (22 mi) from the epicentre. In Arecibo, 23 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.

Likely felt in: Arecibo 23 km, intensity II · Hatillo 25 km, intensity II · Barceloneta 31 km, intensity II · Quebradillas 34 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1,300 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 250,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 11,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 7,900× the energy of this one
  4. This earthquake M 3.1 about 1,300 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.4× 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 4.0 on 2017-03-24 — about 22 times the energy of this one.

Before 2016, the USGS record lists 10 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 61 km N of Hatillo, Puerto Rico · 42 km NNW of this epicentre
  2. 5.8 12 km N of Garrochales, Puerto Rico · 19 km SE of this epicentre
  3. 5.8 4 km E of Moca, Puerto Rico · 50 km SW of this epicentre
  4. 5.6 57 km N of Isabela, Puerto Rico · 44 km NNW of this epicentre
  5. 5.5 64 km N of Tierras Nuevas Poniente, Puerto Rico · 47 km NNE 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 18.6780, -66.7025. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Arecibo Municipio, PR 27 km (17 mi) S earthquakes near Arecibo Municipio
Barceloneta Municipio, PR 28 km (17 mi) SSE earthquakes near Barceloneta Municipio
Hatillo Municipio, PR 28 km (18 mi) SSW earthquakes near Hatillo Municipio
Camuy Municipio, PR 31 km (19 mi) SSW earthquakes near Camuy Municipio
Quebradillas Municipio, PR 33 km (21 mi) SW earthquakes near Quebradillas Municipio
Manatí Municipio, PR 34 km (21 mi) SE earthquakes near Manatí Municipio

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

Aftershocks so far

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

  1. 2.6 17 km N of Tierras Nuevas Poniente, Puerto Rico
  2. 2.5 3 km NW of Barahona, Puerto Rico
  3. 2.4 47 km N of Brenas, Puerto Rico
  4. 2.8 7 km ENE of Arecibo, Puerto Rico
  5. 2.8 2 km NNW of Barceloneta, Puerto Rico
  6. 2.8 12 km N of Quebradillas, Puerto Rico
  7. 2.9 12 km NNE of Isabela, Puerto Rico
  8. 3.1 7 km NNW of Vega Baja, Puerto Rico
  9. 2.8 16 km NNE of Carrizales, Puerto Rico
  10. 2.6 28 km NNW of Tierras Nuevas Poniente, Puerto Rico
  11. 1.9 23 km NNE of Arecibo, Puerto Rico
  12. 2.4 20 km N of Hatillo, Puerto Rico
  13. 2.8 27 km N of Arecibo, Puerto Rico
  14. 2.5 8 km NNE of Carrizales, Puerto Rico
  15. 2.6 11 km NE of Isabela, 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.