QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9md

69 km N of Arecibo, Puerto Rico

Yes. A magnitude 2.9 earthquake was recorded 69 km N of Arecibo, Puerto Rico, 94 km (59 mi) NW of San Juan, PR, at 6:46 pm AST on 5 January 2021 (22:46 UTC), 51 km deep.

94 km (59 mi) NW of San Juan, PR

· 51 km deep · released about 650 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Barceloneta Municipio 69 kmManatí Municipio 73 kmVega Baja Municipio 74 kmArecibo Municipio 74 kmHatillo Municipio 76 kmDorado Municipio 77 kmCamuy Municipio 78 kmVega Alta Municipio 78 kmQuebradillas Municipio 78 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
Magnitude
M 2.9 (md)
Depth
51 km below the surface
Felt
no reports yet
Nearest
Barceloneta Municipio, 69 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2136 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. 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 650 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 23,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 16,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.5× the energy of this one
  4. This earthquake M 2.9 about 650 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 730 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 · 24 km WSW of this epicentre
  2. 6.0 81 km N of Isabela, Puerto Rico · 39 km WNW of this epicentre
  3. 5.9 78 km N of Arecibo, Puerto Rico · 11 km NNW of this epicentre
  4. 5.7 78 km N of Tierras Nuevas Poniente, Puerto Rico · 9 km NNE of this epicentre
  5. 5.6 57 km N of Isabela, Puerto Rico · 37 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 19.0930, -66.5883. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Barceloneta Municipio, PR 69 km (43 mi) S earthquakes near Barceloneta Municipio
Manatí Municipio, PR 73 km (45 mi) S earthquakes near Manatí Municipio
Vega Baja Municipio, PR 74 km (46 mi) SSE earthquakes near Vega Baja Municipio
Arecibo Municipio, PR 74 km (46 mi) S earthquakes near Arecibo Municipio
Hatillo Municipio, PR 76 km (47 mi) SSW earthquakes near Hatillo Municipio
Dorado Municipio, PR 77 km (48 mi) SSE earthquakes near Dorado Municipio

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

Aftershocks so far

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

  1. 3.9 47 km N of Hatillo, Puerto Rico
  2. 3.1 35 km NNW of Brenas, Puerto Rico
  3. 3.3 62 km NNE of Isabela, Puerto Rico
  4. 3.2 57 km N of Hatillo, Puerto Rico
  5. 2.5 65 km N of Tierras Nuevas Poniente, Puerto Rico
  6. 3.1 71 km N of San Juan, Puerto Rico
  7. 3.0 54 km N of Carrizales, Puerto Rico
  8. 3.2 91 km N of Hatillo, Puerto Rico
  9. 3.5 49 km N of Hatillo, Puerto Rico
  10. 3.2 73 km N of Tierras Nuevas Poniente, Puerto Rico
  11. 3.0 63 km N of Hatillo, Puerto Rico
  12. 2.9 54 km N of Brenas, Puerto Rico
  13. 3.0 47 km NNE of Carrizales, Puerto Rico
  14. 3.2 76 km N of Tierras Nuevas Poniente, Puerto Rico
  15. 3.3 85 km N of Tierras Nuevas Poniente, 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.