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 4:31 pm AST (20:31 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 48 km (30 mi) west-northwest of Arecibo, PR, at 4:22 am AST on 18 November 2017 (08:22 UTC), 76 km deep.

USGS: 17 km N of San Antonio, Puerto Rico

47 km (29 mi) WNW of Arecibo, PR · 115 km (72 mi) WNW of San Juan, PR

4:22 am AST, Nov 18, 2017 · · 76 km deep · released about 46 lb of TNT

Every earthquake near Arecibo Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Aguadilla Municipio 18 kmIsabela Municipio 22 kmQuebradillas Municipio 29 kmMoca Municipio 30 kmAguada Municipio 31 kmCamuy Municipio 36 kmRincón Municipio 36 kmSan Sebastián Municipio 39 kmAñasco Municipio 40 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
4:22 am AST on 18 November 2017 ()
Where
48 km (30 mi) west-northwest of Arecibo, PR · earthquakes near Arecibo
Magnitude
M 2.1 (md)
Depth
76 km below the surface
Felt
no reports yet
Nearest
Aguadilla Municipio, 18 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3280 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, 48 km away, the estimate is intensity I (not felt). 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: Isabela, Rafael Hernandez, Caban, Mora, Aceitunas, Aguadilla.

How big was it?

This earthquake released about 46 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 5.8 330,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 230,000× the energy of this one
  3. Around the size people start to feel M 3.0 21× the energy of this one
  4. This earthquake M 2.1 about 46 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 4.3 on 2017-10-14 — about 1,900 times the energy of this one.

Before 2016, the USGS record lists 14 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.7 45 km N of San Antonio, Puerto Rico · 29 km N of this epicentre
  2. 7.1 24 km NNW of San Antonio, Puerto Rico · 9 km NW of this epicentre
  3. 6.4 32 km NW of Aguadilla, Puerto Rico · 27 km W of this epicentre
  4. 6.3 6 km WNW of Aguadilla, Puerto Rico · 24 km SSW of this epicentre
  5. 6.1 15 km WNW of San Antonio, Puerto Rico · 15 km SW 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 18.6453, -67.1286. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Aguadilla Municipio, PR 18 km (11 mi) S earthquakes near Aguadilla Municipio
Isabela Municipio, PR 22 km (13 mi) SE earthquakes near Isabela Municipio
Quebradillas Municipio, PR 29 km (18 mi) SE earthquakes near Quebradillas Municipio
Moca Municipio, PR 30 km (19 mi) S earthquakes near Moca Municipio
Aguada Municipio, PR 31 km (19 mi) SSW earthquakes near Aguada Municipio
Camuy Municipio, PR 36 km (22 mi) SE earthquakes near Camuy Municipio

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

Aftershocks so far

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

  1. 2.7 20 km W of Rincón, Puerto Rico
  2. 2.3 5 km N of Hatillo, Puerto Rico
  3. 2.3 32 km NW of San Antonio, Puerto Rico
  4. 2.7 19 km WNW of Rincón, Puerto Rico
  5. 2.7 21 km W of Rincón, Puerto Rico
  6. 3.2 57 km NNE of Isabela, Puerto Rico
  7. 2.5 Mona Passage
  8. 2.8 39 km NW of San Antonio, Puerto Rico
  9. 2.8 56 km N of Hatillo, Puerto Rico
  10. 3.0 11 km N of Camuy, Puerto Rico
  11. 2.5 18 km N of Arecibo, Puerto Rico
  12. 2.9 6 km NNW of Camuy, Puerto Rico
  13. 3.0 65 km N of Isabela, Puerto Rico
  14. 3.1 53 km N of Isabela, Puerto Rico
  15. 2.5 0 km NNE of Mayagüez, 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.