QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9md

107 km NNE of San Juan, Puerto Rico

· 27 km deep · released about 11 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Loíza Municipio 107 kmCataño Municipio 112 kmToa Baja Municipio 112 kmSan Juan Municipio 112 kmDorado Municipio 113 kmCarolina Municipio 113 kmRío Grande Municipio 115 kmLuquillo Municipio 116 kmFajardo Municipio 116 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 3.9 (md)
Depth
27 km below the surface
Felt
no reports yet
Nearest
Loíza Municipio, 107 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1265 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

How big was it?

This earthquake released about 11 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.9 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 16,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 710× the energy of this one
  3. Magna, Utah 2020 M 5.7 500× the energy of this one
  4. This earthquake M 3.9 about 11 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 22× 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 19.4056, -65.8381. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Loíza Municipio, PR 107 km (67 mi) N of here earthquakes near Loíza Municipio
Cataño Municipio, PR 112 km (69 mi) NNE of here earthquakes near Cataño Municipio
Toa Baja Municipio, PR 112 km (70 mi) NNE of here earthquakes near Toa Baja Municipio
San Juan Municipio, PR 112 km (70 mi) NNE of here earthquakes near San Juan Municipio
Dorado Municipio, PR 113 km (70 mi) NNE of here earthquakes near Dorado Municipio
Carolina Municipio, PR 113 km (70 mi) N of here earthquakes near Carolina 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. 3.8 146 km N of Suárez, Puerto Rico
  2. 3.4 144 km N of Suárez, Puerto Rico
  3. 3.8 134 km N of Su?rez, Puerto Rico
  4. 3.4 119 km N of Suárez, Puerto Rico
  5. 3.8 121 km N of Suárez, Puerto Rico
  6. 3.3 153 km N of Suárez, Puerto Rico
  7. 3.9 Puerto Rico region
  8. 3.4 69 km NNE of Suárez, Puerto Rico
  9. 3.7 139 km N of Suárez, Puerto Rico
  10. 4.1 139 km N of Suárez, Puerto Rico
  11. 4.1 132 km N of Suárez, Puerto Rico
  12. 4.0 109 km N of Suárez, Puerto Rico
  13. 4.0 Puerto Rico region
  14. 4.1 141 km N of Suárez, Puerto Rico
  15. 4.0 128 km N of Suárez, 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 4.3 on 2022-12-25 — it released about 4.7 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.