QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7md

Earthquake near Arecibo, PR

No earthquake was likely felt in Arecibo in the 24 hours to 12:59 pm AST (16:59 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 2.7 earthquake was recorded 28 km (18 mi) north of Arecibo, PR, at 10:42 pm AST on 8 September 2018 (02:42 UTC), 48 km deep.

USGS: 28 km N of Arecibo, Puerto Rico

73 km (45 mi) WNW of San Juan, PR · 31 km (19 mi) NNE of Arecibo, PR

10:42 pm AST, Sep 8, 2018 · · 48 km deep · released about 360 lb of TNT

Every earthquake near Arecibo Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Barceloneta Municipio 30 kmArecibo Municipio 32 kmHatillo Municipio 34 kmManatí Municipio 36 kmCamuy Municipio 37 kmQuebradillas Municipio 40 kmFlorida Municipio 41 kmVega Baja Municipio 41 kmIsabela Municipio 45 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
10:42 pm AST on 8 September 2018 ()
Where
28 km (18 mi) north of Arecibo, PR · earthquakes near Arecibo
Magnitude
M 2.7 (md)
Depth
48 km below the surface
Felt
no reports yet
Nearest
Barceloneta Municipio, 30 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2985 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 it was probably too small to be felt, even directly above it. In Arecibo, 28 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.

Earthquakes near other towns within 30 km: Carrizales.

How big was it?

This earthquake released about 360 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 42,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 30,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.6× the energy of this one
  4. This earthquake M 2.7 about 360 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 1,300 times the energy of this one.

Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 61 km N of Hatillo, Puerto Rico · 39 km NNW of this epicentre
  2. 5.8 12 km N of Garrochales, Puerto Rico · 21 km SSE of this epicentre
  3. 5.6 57 km N of Isabela, Puerto Rico · 42 km NW of this epicentre
  4. 5.5 64 km N of Tierras Nuevas Poniente, Puerto Rico · 41 km NNE of this epicentre
  5. 5.5 Puerto Rico region · 42 km NW 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 18.7233, -66.6663. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Barceloneta Municipio, PR 30 km (19 mi) SSE earthquakes near Barceloneta Municipio
Arecibo Municipio, PR 32 km (20 mi) S earthquakes near Arecibo Municipio
Hatillo Municipio, PR 34 km (21 mi) SSW earthquakes near Hatillo Municipio
Manatí Municipio, PR 36 km (22 mi) SSE earthquakes near Manatí Municipio
Camuy Municipio, PR 37 km (23 mi) SW earthquakes near Camuy Municipio
Quebradillas Municipio, PR 40 km (25 mi) SW earthquakes near Quebradillas Municipio

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

Aftershocks so far

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

  1. 2.9 65 km NNE of Arecibo, Puerto Rico
  2. 2.5 55 km N of Tierras Nuevas Poniente, Puerto Rico
  3. 2.3 71 km N of Tierras Nuevas Poniente, Puerto Rico
  4. 2.8 61 km N of Tierras Nuevas Poniente, Puerto Rico
  5. 2.9 67 km N of Tierras Nuevas Poniente, Puerto Rico
  6. 2.4 70 km N of Tierras Nuevas Poniente, Puerto Rico
  7. 2.5 57 km N of Hatillo, Puerto Rico
  8. 2.8 61 km NNE of Isabela, Puerto Rico
  9. 2.4 60 km N of Hatillo, Puerto Rico
  10. 2.3 9 km NNE of Carrizales, Puerto Rico
  11. 2.5 44 km N of Isabela, Puerto Rico
  12. 2.4 24 km N of Isabela, Puerto Rico
  13. 2.9 59 km NNE of Arecibo, Puerto Rico
  14. 2.8 40 km N of Dorado, Puerto Rico
  15. 2.4 8 km NNE of Dorado, 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.