QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5Md

Earthquake near Arecibo, PR

No earthquake was likely felt in Arecibo in the 24 hours to 3:06 am AST (07:06 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 2.5 earthquake was recorded 40 km (25 mi) north-northwest of Arecibo, PR, at 3:05 pm AST on 9 August 2016 (19:05 UTC), 65 km deep.

USGS: 35 km N of Hatillo, Puerto Rico

95 km (59 mi) WNW of San Juan, PR · 41 km (26 mi) NNW of Arecibo, PR

3:05 pm AST, Aug 9, 2016 · · 65 km deep · released about 170 lb of TNT

Every earthquake near Arecibo Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Quebradillas Municipio 38 kmIsabela Municipio 39 kmCamuy Municipio 40 kmHatillo Municipio 41 kmArecibo Municipio 46 kmAguadilla Municipio 47 kmBarceloneta Municipio 49 kmMoca Municipio 53 kmSan Sebastián Municipio 54 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
3:05 pm AST on 9 August 2016 ()
Where
40 km (25 mi) north-northwest of Arecibo, PR · earthquakes near Arecibo
Magnitude
M 2.5 (Md)
Depth
65 km below the surface
Felt
no reports yet
Nearest
Quebradillas Municipio, 38 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3669 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, 40 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.

How big was it?

This earthquake released about 170 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 89,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 63,000× the energy of this one
  3. Around the size people start to feel M 3.0 5.6× the energy of this one
  4. This earthquake M 2.5 about 170 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 19 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.7 45 km N of San Antonio, Puerto Rico · 29 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 · 27 km NNE of this epicentre
  4. 6.1 15 km WNW of San Antonio, Puerto Rico · 48 km SW of this epicentre
  5. 6.1 18 km NNW of San Antonio, Puerto Rico · 38 km WSW 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 18.8043, -66.8626. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Quebradillas Municipio, PR 38 km (24 mi) S earthquakes near Quebradillas Municipio
Isabela Municipio, PR 39 km (24 mi) SSW earthquakes near Isabela Municipio
Camuy Municipio, PR 40 km (25 mi) S earthquakes near Camuy Municipio
Hatillo Municipio, PR 41 km (25 mi) S earthquakes near Hatillo Municipio
Arecibo Municipio, PR 46 km (28 mi) SSE earthquakes near Arecibo Municipio
Aguadilla Municipio, PR 47 km (29 mi) SW earthquakes near Aguadilla 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. 2.8 70 km N of Isabela, Puerto Rico
  2. 2.7 13 km N of Arecibo, Puerto Rico
  3. 3.1 41 km NW of San Antonio, Puerto Rico
  4. 2.9 71 km N of Arecibo, Puerto Rico
  5. 3.2 2 km NNW of Hatillo, Puerto Rico
  6. 2.4 17 km N of Camuy, Puerto Rico
  7. 3.1 55 km NNW of San Antonio, Puerto Rico
  8. 2.4 15 km NNE of Carrizales, Puerto Rico
  9. 2.7 10 km NNE of Arecibo, Puerto Rico
  10. 3.0 23 km N of Hatillo, Puerto Rico
  11. 2.9 60 km N of Hatillo, Puerto Rico
  12. 2.7 9 km N of Animas, Puerto Rico
  13. 3.1 66 km N of San Antonio, Puerto Rico
  14. 2.7 49 km N of Carrizales, Puerto Rico
  15. 2.9 61 km N of Isabela, 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.