QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4md

Earthquake near Arecibo, PR

No earthquake was likely felt in Arecibo in the 24 hours to 4:23 pm AST (20:23 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 2.4 earthquake was recorded 35 km (22 mi) north-northwest of Arecibo, PR, at 8:00 pm AST on 16 December 2018 (00:00 UTC), 9.0 km deep.

USGS: 30 km N of Hatillo, Puerto Rico

92 km (57 mi) WNW of San Juan, PR · 36 km (23 mi) NNW of Arecibo, PR

8:00 pm AST, Dec 16, 2018 · · 9.0 km deep · released about 130 lb of TNT

Every earthquake near Arecibo Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Quebradillas Municipio 34 kmIsabela Municipio 35 kmCamuy Municipio 35 kmHatillo Municipio 36 kmArecibo Municipio 41 kmAguadilla Municipio 44 kmBarceloneta Municipio 45 kmMoca Municipio 49 kmSan Sebastián Municipio 49 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
8:00 pm AST on 16 December 2018 ()
Where
35 km (22 mi) north-northwest of Arecibo, PR · earthquakes near Arecibo
Magnitude
M 2.4 (md)
Depth
9.0 km below the surface
Felt
no reports yet
Nearest
Quebradillas Municipio, 34 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2887 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 20 km (12 mi) from the epicentre. In Arecibo, 35 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 130 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 80,000× the energy of this one
  3. Around the size people start to feel M 3.0 7.2× the energy of this one
  4. This earthquake M 2.4 about 130 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 2,200 times the energy of this one.

Before 2016, the USGS record lists 15 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.7 45 km N of San Antonio, Puerto Rico · 32 km WNW of this epicentre
  2. 7.1 24 km NNW of San Antonio, Puerto Rico · 36 km W of this epicentre
  3. 6.4 61 km N of Hatillo, Puerto Rico · 32 km N of this epicentre
  4. 6.1 15 km WNW of San Antonio, Puerto Rico · 46 km WSW of this epicentre
  5. 6.1 18 km NNW of San Antonio, Puerto Rico · 37 km WSW 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 18.7618, -66.8550. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Quebradillas Municipio, PR 34 km (21 mi) SSW earthquakes near Quebradillas Municipio
Isabela Municipio, PR 35 km (22 mi) SSW earthquakes near Isabela Municipio
Camuy Municipio, PR 35 km (22 mi) S earthquakes near Camuy Municipio
Hatillo Municipio, PR 36 km (22 mi) S earthquakes near Hatillo Municipio
Arecibo Municipio, PR 41 km (26 mi) SSE earthquakes near Arecibo Municipio
Aguadilla Municipio, PR 44 km (27 mi) SW earthquakes near Aguadilla Municipio

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

Aftershocks so far

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

  1. 2.3 19 km NNE of Isabela, Puerto Rico
  2. 2.5 13 km N of Isabela, Puerto Rico
  3. 1.8 3 km W of Rafael Capo, Puerto Rico
  4. 3.1 58 km N of San Antonio, Puerto Rico
  5. 2.2 4 km ENE of Isabela, Puerto Rico
  6. 1.8 1 km SE of Piedra Gorda, Puerto Rico
  7. 2.6 62 km NNE of Arecibo, Puerto Rico
  8. 2.9 49 km N of Hatillo, Puerto Rico
  9. 2.4 13 km N of Carrizales, Puerto Rico
  10. 3.0 46 km NNW of San Antonio, Puerto Rico
  11. 1.5 18 km NNE of Tierras Nuevas Poniente, Puerto Rico
  12. 2.6 41 km NNW of San Antonio, Puerto Rico
  13. 2.6 32 km N of Garrochales, Puerto Rico
  14. 2.4 34 km N of Arecibo, Puerto Rico
  15. 2.5 18 km NNW of Camuy, 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.