QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

Earthquake near Arecibo, PR

No earthquake was likely felt in Arecibo in the 24 hours to 8:35 pm AST (00:35 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 1.9 earthquake was recorded 6 km (4 mi) north of Arecibo, PR, at 5:11 am AST on 18 September 2018 (09:11 UTC), 19 km deep.

USGS: 5 km N of Arecibo, Puerto Rico

8 km (5 mi) NNE of Arecibo, PR · 69 km (43 mi) WNW of San Juan, PR

5:11 am AST, Sep 18, 2018 · · 19 km deep · released about 25 lb of TNT

Every earthquake near Arecibo Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Arecibo Municipio 11 kmHatillo Municipio 14 kmBarceloneta Municipio 17 kmCamuy Municipio 19 kmFlorida Municipio 23 kmManatí Municipio 24 kmQuebradillas Municipio 24 kmUtuado Municipio 28 kmCiales Municipio 32 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
5:11 am AST on 18 September 2018 ()
Where
6 km (4 mi) north of Arecibo, PR · earthquakes near Arecibo
Magnitude
M 1.9 (md)
Depth
19 km below the surface
Felt
no reports yet
Nearest
Arecibo Municipio, 11 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2977 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. 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.

Earthquakes near other towns within 30 km: Carrizales, Corcovado, Bajadero, Animas, Hatillo, Rafael Gonzalez.

How big was it?

This earthquake released about 25 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 620,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 440,000× the energy of this one
  3. Around the size people start to feel M 3.0 39× the energy of this one
  4. This earthquake M 1.9 about 25 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

  1. 5.8 12 km N of Garrochales, Puerto Rico · 15 km ENE of this epicentre
  2. 5.8 4 km E of Moca, Puerto Rico · 41 km WSW of this epicentre
  3. 5.0 3 km N of Brenas, Puerto Rico · 38 km E 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 18.5246, -66.7051. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Arecibo Municipio, PR 11 km (7 mi) SSE earthquakes near Arecibo Municipio
Hatillo Municipio, PR 14 km (8 mi) SW earthquakes near Hatillo Municipio
Barceloneta Municipio, PR 17 km (10 mi) ESE earthquakes near Barceloneta Municipio
Camuy Municipio, PR 19 km (12 mi) WSW earthquakes near Camuy Municipio
Florida Municipio, PR 23 km (14 mi) SE earthquakes near Florida Municipio
Manatí Municipio, PR 24 km (15 mi) ESE earthquakes near Manatí Municipio

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

Aftershocks so far

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

  1. 2.5 3 km E of Moca, Puerto Rico
  2. 2.3 23 km NNE of Isabela, Puerto Rico
  3. 2.0 10 km E of Maricao, Puerto Rico
  4. 1.9 5 km NW of Adjuntas, Puerto Rico
  5. 2.3 9 km NNE of Carrizales, Puerto Rico
  6. 2.3 3 km NNE of Espino, Puerto Rico
  7. 1.6 12 km NE of Sabana Grande, Puerto Rico
  8. 2.4 24 km N of Isabela, Puerto Rico
  9. 2.2 2 km NW of Moca, Puerto Rico
  10. 2.2 6 km WNW of Las Marías, Puerto Rico
  11. 2.4 8 km NNE of Dorado, Puerto Rico
  12. 2.0 1 km SW of Maricao, Puerto Rico
  13. 1.9 3 km SE of Maricao, Puerto Rico
  14. 1.7 2 km N of Maricao, Puerto Rico
  15. 1.9 4 km SW of Adjuntas, 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.