QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Arecibo, PR

No earthquake was likely felt in Arecibo in the 24 hours to 7:40 pm AST (23:40 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 2.1 earthquake was recorded 6 km (4 mi) north-northwest of Arecibo, PR, at 7:47 pm AST on 22 December 2018 (23:47 UTC), 14 km deep.

USGS: Puerto Rico region

7 km (5 mi) N of Arecibo, PR · 72 km (45 mi) W of San Juan, PR

7:47 pm AST, Dec 22, 2018 · · 14 km deep · released about 41 lb of TNT

Every earthquake near Arecibo Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Hatillo Municipio 11 kmArecibo Municipio 11 kmCamuy Municipio 16 kmBarceloneta Municipio 19 kmQuebradillas Municipio 21 kmFlorida Municipio 25 kmManatí Municipio 27 kmUtuado Municipio 28 kmIsabela Municipio 30 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
7:47 pm AST on 22 December 2018 ()
Where
6 km (4 mi) north-northwest of Arecibo, PR · earthquakes near Arecibo
Magnitude
M 2.1 (md)
Depth
14 km below the surface
Felt
no reports yet
Nearest
Hatillo Municipio, 11 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2881 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 10 km (6 mi) from the epicentre. In Arecibo, 6 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 6 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 41 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 370,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 260,000× the energy of this one
  3. Around the size people start to feel M 3.0 23× the energy of this one
  4. This earthquake M 2.1 about 41 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 in our catalogue was M 4.4 on 2018-12-09 — about 2,900 times the energy of this one.

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 18.5206, -66.7325. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Hatillo Municipio, PR 11 km (7 mi) SW earthquakes near Hatillo Municipio
Arecibo Municipio, PR 11 km (7 mi) SSE earthquakes near Arecibo Municipio
Camuy Municipio, PR 16 km (10 mi) WSW earthquakes near Camuy Municipio
Barceloneta Municipio, PR 19 km (12 mi) ESE earthquakes near Barceloneta Municipio
Quebradillas Municipio, PR 21 km (13 mi) WSW earthquakes near Quebradillas Municipio
Florida Municipio, PR 25 km (15 mi) SE earthquakes near Florida 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. 2.5 13 km N of Isabela, Puerto Rico
  2. 1.9 11 km ESE of Maricao, Puerto Rico
  3. 1.8 3 km W of Rafael Capo, Puerto Rico
  4. 2.0 3 km SW of Adjuntas, Puerto Rico
  5. 2.2 4 km ENE of Isabela, Puerto Rico
  6. 2.9 13 km NNW of Brenas, Puerto Rico
  7. 1.8 1 km SE of Piedra Gorda, Puerto Rico
  8. 2.9 49 km N of Hatillo, Puerto Rico
  9. 2.4 13 km N of Carrizales, Puerto Rico
  10. 1.5 18 km NNE of Tierras Nuevas Poniente, Puerto Rico
  11. 2.5 12 km N of Brenas, Puerto Rico
  12. 2.6 32 km N of Garrochales, Puerto Rico
  13. 2.4 34 km N of Arecibo, Puerto Rico
  14. 2.5 18 km NNW of Camuy, Puerto Rico
  15. 1.6 19 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.