QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9md

61 km NW of San Antonio, Puerto Rico

Yes. A magnitude 2.9 earthquake was recorded 61 km NW of San Antonio, Puerto Rico, at 10:12 am AST on 31 January 2018 (14:12 UTC), 54 km deep.

· 54 km deep · released about 610 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Aguadilla Municipio 59 kmRincón Municipio 64 kmAguada Municipio 64 kmIsabela Municipio 69 kmMoca Municipio 71 kmAñasco Municipio 76 kmQuebradillas Municipio 78 kmSan Sebastián Municipio 83 kmCamuy Municipio 85 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
54 km below the surface
Felt
no reports yet
Nearest
Aguadilla Municipio, 59 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3206 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 610 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 25,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 18,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.6× the energy of this one
  4. This earthquake M 2.9 about 610 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 4.4 on 2017-10-01 — about 200 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 · 46 km E of this epicentre
  2. 7.1 24 km NNW of San Antonio, Puerto Rico · 41 km ESE of this epicentre
  3. 6.8 94 km NE of Punta Cana, Dominican Republic · 37 km NNW of this epicentre
  4. 6.4 32 km NW of Aguadilla, Puerto Rico · 30 km SE of this epicentre
  5. 6.3 58 km E of Punta Cana, Dominican Republic · 50 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 18.8385, -67.5508. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Aguadilla Municipio, PR 59 km (36 mi) SE earthquakes near Aguadilla Municipio
Rincón Municipio, PR 64 km (40 mi) SSE earthquakes near Rincón Municipio
Aguada Municipio, PR 64 km (40 mi) SE earthquakes near Aguada Municipio
Isabela Municipio, PR 69 km (43 mi) SE earthquakes near Isabela Municipio
Moca Municipio, PR 71 km (44 mi) SE earthquakes near Moca Municipio
Añasco Municipio, PR 76 km (47 mi) SE earthquakes near Añasco Municipio

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

Aftershocks so far

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

  1. 3.2 79 km NW of San Antonio, Puerto Rico
  2. 2.5 38 km NW of Rincón, Puerto Rico
  3. 2.6 45 km NW of San Antonio, Puerto Rico
  4. 2.9 34 km WNW of Rincón, Puerto Rico
  5. 2.8 62 km E of Punta Cana, Dominican Republic
  6. 3.1 61 km NNW of San Antonio, Puerto Rico
  7. 2.7 67 km NW of Rincón, Puerto Rico
  8. 2.7 38 km NW of Aguadilla, Puerto Rico
  9. 3.1 60 km NNW of San Antonio, Puerto Rico
  10. 1.9 51 km NE of Punta Cana, Dominican Republic
  11. 3.1 64 km NW of San Antonio, Puerto Rico
  12. 2.7 36 km WNW of Rincón, Puerto Rico
  13. 2.7 75 km NE of Punta Cana, Dominican Republic
  14. 2.5 32 km NW of San Antonio, Puerto Rico
  15. 2.7 86 km NNW 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.