QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

Earthquake near Arecibo, PR

No earthquake was likely felt in Arecibo in the 24 hours to 12:21 am AST (04:21 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 2.3 earthquake was recorded 34 km (21 mi) north of Arecibo, PR, at 7:54 am AST on 21 January 2018 (11:54 UTC), 14 km deep.

USGS: 33 km N of Arecibo, Puerto Rico

79 km (49 mi) WNW of San Juan, PR · 36 km (22 mi) N of Arecibo, PR

7:54 am AST, Jan 21, 2018 · · 14 km deep · released about 94 lb of TNT

Every earthquake near Arecibo Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Barceloneta Municipio 37 kmArecibo Municipio 38 kmHatillo Municipio 38 kmCamuy Municipio 40 kmQuebradillas Municipio 41 kmManatí Municipio 43 kmIsabela Municipio 46 kmFlorida Municipio 48 kmVega Baja Municipio 48 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
7:54 am AST on 21 January 2018 ()
Where
34 km (21 mi) north of Arecibo, PR · earthquakes near Arecibo
Magnitude
M 2.3 (md)
Depth
14 km below the surface
Felt
no reports yet
Nearest
Barceloneta Municipio, 37 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3217 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 14 km (9 mi) from the epicentre. In Arecibo, 34 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 94 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 160,000× 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 10× the energy of this one
  4. This earthquake M 2.3 about 94 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 4.8 on 2017-08-18 — about 5,100 times the energy of this one.

Before 2016, the USGS record lists 13 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.7 45 km N of San Antonio, Puerto Rico · 46 km WNW of this epicentre
  2. 6.4 61 km N of Hatillo, Puerto Rico · 32 km NNW of this epicentre
  3. 5.9 78 km N of Arecibo, Puerto Rico · 45 km N of this epicentre
  4. 5.8 12 km N of Garrochales, Puerto Rico · 28 km SSE of this epicentre
  5. 5.7 78 km N of Tierras Nuevas Poniente, Puerto Rico · 46 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 18.7746, -66.7086. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Barceloneta Municipio, PR 37 km (23 mi) SSE earthquakes near Barceloneta Municipio
Arecibo Municipio, PR 38 km (24 mi) S earthquakes near Arecibo Municipio
Hatillo Municipio, PR 38 km (24 mi) SSW earthquakes near Hatillo Municipio
Camuy Municipio, PR 40 km (25 mi) SSW earthquakes near Camuy Municipio
Quebradillas Municipio, PR 41 km (26 mi) SW earthquakes near Quebradillas Municipio
Manatí Municipio, PR 43 km (27 mi) SSE earthquakes near Manatí Municipio

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

Aftershocks so far

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

  1. 2.5 73 km N of Brenas, Puerto Rico
  2. 2.7 22 km N of Tierras Nuevas Poniente, Puerto Rico
  3. 2.9 22 km NNE of Isabela, Puerto Rico
  4. 2.5 17 km N of Carrizales, Puerto Rico
  5. 2.6 45 km N of Tierras Nuevas Poniente, Puerto Rico
  6. 2.7 54 km N of Isabela, Puerto Rico
  7. 2.3 Puerto Rico region
  8. 2.7 Puerto Rico region
  9. 2.6 47 km N of Garrochales, Puerto Rico
  10. 2.6 19 km NNE of Arecibo, Puerto Rico
  11. 2.8 31 km NNW of San Antonio, Puerto Rico
  12. 3.0 54 km N of Carrizales, Puerto Rico
  13. 2.8 40 km N of Tierras Nuevas Poniente, Puerto Rico
  14. 3.2 67 km NNE of Arecibo, Puerto Rico
  15. 2.9 65 km N of Tierras Nuevas Poniente, 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.