QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8md

Earthquake near Arecibo, PR

No earthquake was likely felt in Arecibo in the 24 hours to 5:41 pm AST (21:41 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 2.8 earthquake was recorded 45 km (28 mi) north-northwest of Arecibo, PR, at 3:16 am AST on 2 September 2017 (07:16 UTC), 10 km deep.

USGS: 40 km N of Hatillo, Puerto Rico

100 km (62 mi) WNW of San Juan, PR · 46 km (29 mi) NNW of Arecibo, PR

3:16 am AST, Sep 2, 2017 · · 10 km deep · released about 530 lb of TNT

Every earthquake near Arecibo Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Quebradillas Municipio 43 kmIsabela Municipio 43 kmCamuy Municipio 45 kmHatillo Municipio 46 kmAguadilla Municipio 49 kmArecibo Municipio 51 kmBarceloneta Municipio 54 kmMoca Municipio 56 kmSan Sebastián Municipio 58 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
3:16 am AST on 2 September 2017 ()
Where
45 km (28 mi) north-northwest of Arecibo, PR · earthquakes near Arecibo
Magnitude
M 2.8 (md)
Depth
10 km below the surface
Felt
no reports yet
Nearest
Quebradillas Municipio, 43 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3357 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, people at rest would likely notice it out to about 27 km (17 mi) from the epicentre. In Arecibo, 45 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 530 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 29,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 20,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.8× the energy of this one
  4. This earthquake M 2.8 about 530 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 560 times the energy of this one.

Before 2016, the USGS record lists 20 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.7 45 km N of San Antonio, Puerto Rico · 25 km WNW of this epicentre
  2. 7.1 24 km NNW of San Antonio, Puerto Rico · 36 km WSW of this epicentre
  3. 6.4 61 km N of Hatillo, Puerto Rico · 23 km NNE of this epicentre
  4. 6.1 15 km WNW of San Antonio, Puerto Rico · 49 km SW of this epicentre
  5. 6.1 18 km NNW of San Antonio, Puerto Rico · 39 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 18.8473, -66.8851. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Quebradillas Municipio, PR 43 km (26 mi) S earthquakes near Quebradillas Municipio
Isabela Municipio, PR 43 km (26 mi) SSW earthquakes near Isabela Municipio
Camuy Municipio, PR 45 km (28 mi) S earthquakes near Camuy Municipio
Hatillo Municipio, PR 46 km (29 mi) SSE earthquakes near Hatillo Municipio
Aguadilla Municipio, PR 49 km (30 mi) SW earthquakes near Aguadilla Municipio
Arecibo Municipio, PR 51 km (32 mi) SSE earthquakes near Arecibo Municipio

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

Aftershocks so far

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

  1. 3.0 68 km NNE of Arecibo, Puerto Rico
  2. 2.7 19 km NW of San Antonio, Puerto Rico
  3. 3.2 42 km NNW of San Antonio, Puerto Rico
  4. 3.1 4 km NNE of Hatillo, Puerto Rico
  5. 3.3 59 km NNW of San Antonio, Puerto Rico
  6. 2.7 12 km NW of San Antonio, Puerto Rico
  7. 3.0 Puerto Rico region
  8. 2.9 71 km N of Hatillo, Puerto Rico
  9. 2.7 46 km N of Hatillo, Puerto Rico
  10. 2.6 29 km NNW of San Antonio, Puerto Rico
  11. 3.1 28 km N of Tierras Nuevas Poniente, Puerto Rico
  12. 1.9 14 km NW of San Antonio, Puerto Rico
  13. 2.8 23 km N of Camuy, Puerto Rico
  14. 2.6 32 km N of Isabela, Puerto Rico
  15. 2.1 17 km N of San Antonio, 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.