QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1md

39 km N of Loíza, Puerto Rico

· 18 km deep · released about 1,600 lb of TNT

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10 km30 km60 km120 km N Loíza Municipio 39 kmCarolina Municipio 45 kmRío Grande Municipio 46 kmSan Juan Municipio 46 kmLuquillo Municipio 49 kmCataño Municipio 49 kmCanóvanas Municipio 51 kmToa Baja Municipio 51 kmTrujillo Alto Municipio 53 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 3.1 (md)
Depth
18 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Loíza Municipio, 39 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 259 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 1 person has reported feeling it to USGS.

How big was it?

This earthquake released about 1,600 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 210,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 9,400× the energy of this one
  3. Magna, Utah 2020 M 5.7 6,700× the energy of this one
  4. This earthquake M 3.1 about 1,600 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.7× more

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.

Where

Epicentre 18.7867, -65.8543. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Loíza Municipio, PR 39 km (24 mi) NNE of here earthquakes near Loíza Municipio
Carolina Municipio, PR 45 km (28 mi) NNE of here earthquakes near Carolina Municipio
Río Grande Municipio, PR 46 km (29 mi) N of here earthquakes near Río Grande Municipio
San Juan Municipio, PR 46 km (29 mi) NNE of here earthquakes near San Juan Municipio
Luquillo Municipio, PR 49 km (30 mi) NNW of here earthquakes near Luquillo Municipio
Cataño Municipio, PR 49 km (31 mi) NE of here earthquakes near Cataño Municipio

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

Aftershocks so far

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

  1. 3.7 65 km NNE of Luquillo, Puerto Rico
  2. 3.1 4 km N of San Juan, Puerto Rico
  3. 2.7 15 km N of San Juan, Puerto Rico
  4. 3.1 55 km NNE of San Juan, Puerto Rico
  5. 3.0 60 km N of Loíza, Puerto Rico
  6. 2.9 23 km NNE of Luquillo, Puerto Rico
  7. 3.2 51 km NNE of Vieques, Puerto Rico
  8. 3.1 3 km ESE of San Juan, Puerto Rico
  9. 3.3 20 km NE of Luquillo, Puerto Rico
  10. 3.2 74 km N of San Juan, Puerto Rico
  11. 3.4 84 km NNE of Vieques, Puerto Rico
  12. 2.5 27 km NNE of Vieques, Puerto Rico
  13. 2.8 17 km N of San Juan, Puerto Rico
  14. 3.4 49 km N of Suárez, Puerto Rico
  15. 3.1 59 km N of Loíza, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.2 on 2023-12-25 — it released about 34 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.