QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0md

Earthquake near Arecibo, PR

No earthquake was likely felt in Arecibo in the 24 hours to 5:26 pm AST (21:26 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 3.0 earthquake was recorded 48 km (30 mi) north-northeast of Arecibo, PR, at 4:30 am AST on 28 October 2019 (08:30 UTC), 85 km deep. 1 person has reported feeling it to USGS.

USGS: 42 km N of Tierras Nuevas Poniente, Puerto Rico

67 km (42 mi) NW of San Juan, PR · 50 km (31 mi) NNE of Arecibo, PR

4:30 am AST, Oct 28, 2019 · · 85 km deep · released about 800 lb of TNT

10 km30 km60 km120 km N Barceloneta Municipio 42 kmManatí Municipio 45 kmVega Baja Municipio 45 kmDorado Municipio 48 kmVega Alta Municipio 49 kmArecibo Municipio 50 kmFlorida Municipio 54 kmToa Baja Municipio 54 kmHatillo Municipio 55 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
4:30 am AST on 28 October 2019 ()
Where
48 km (30 mi) north-northeast of Arecibo, PR · earthquakes near Arecibo
Magnitude
M 3.0 (md)
Depth
85 km below the surface
Felt
1 report · strongest reported intensity III
Nearest
Barceloneta Municipio, 42 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2571 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, 48 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 800 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 420,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 19,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 13,000× the energy of this one
  4. This earthquake M 3.0 about 800 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 600 times the energy of this one.

Before 2016, the USGS record lists 11 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 61 km N of Hatillo, Puerto Rico · 40 km WNW of this epicentre
  2. 5.9 78 km N of Arecibo, Puerto Rico · 40 km NNW of this epicentre
  3. 5.8 12 km N of Garrochales, Puerto Rico · 32 km SSW of this epicentre
  4. 5.7 78 km N of Tierras Nuevas Poniente, Puerto Rico · 36 km N of this epicentre
  5. 5.6 57 km N of Isabela, Puerto Rico · 49 km WNW 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 18.8465, -66.4948. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Barceloneta Municipio, PR 42 km (26 mi) S earthquakes near Barceloneta Municipio
Manatí Municipio, PR 45 km (28 mi) S earthquakes near Manatí Municipio
Vega Baja Municipio, PR 45 km (28 mi) SSE earthquakes near Vega Baja Municipio
Dorado Municipio, PR 48 km (30 mi) SSE earthquakes near Dorado Municipio
Vega Alta Municipio, PR 49 km (30 mi) SSE earthquakes near Vega Alta Municipio
Arecibo Municipio, PR 50 km (31 mi) SSW earthquakes near Arecibo 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. 2.9 85 km N of Tierras Nuevas Poniente, Puerto Rico
  2. 2.6 17 km N of Brenas, Puerto Rico
  3. 2.0 22 km NNE of Carrizales, Puerto Rico
  4. 2.0 61 km N of Hatillo, Puerto Rico
  5. 3.1 81 km N of Tierras Nuevas Poniente, Puerto Rico
  6. 2.7 35 km N of Tierras Nuevas Poniente, Puerto Rico
  7. 2.7 12 km NNE of Dorado, Puerto Rico
  8. 2.8 70 km N of Brenas, Puerto Rico
  9. 2.6 8 km N of Arecibo, Puerto Rico
  10. 2.8 42 km N of Isabela, Puerto Rico
  11. 2.7 28 km N of Camuy, Puerto Rico
  12. 2.6 38 km N of Hatillo, Puerto Rico
  13. 2.4 34 km N of Hatillo, Puerto Rico
  14. 3.0 35 km NNE of Isabela, Puerto Rico
  15. 2.7 40 km NNE 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.