QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9md

83 km N of San Juan, Puerto Rico

· 21 km deep · released about 11 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Loíza Municipio 86 kmToa Baja Municipio 86 kmDorado Municipio 86 kmCataño Municipio 87 kmSan Juan Municipio 88 kmCarolina Municipio 91 kmVega Alta Municipio 93 kmVega Baja Municipio 94 kmRío Grande Municipio 96 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
21 km below the surface
Felt
no reports yet
Nearest
Loíza Municipio, 86 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 443 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 19.2148, -66.0130. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Loíza Municipio, PR 86 km (53 mi) N of here earthquakes near Loíza Municipio
Toa Baja Municipio, PR 86 km (54 mi) NNE of here earthquakes near Toa Baja Municipio
Dorado Municipio, PR 86 km (54 mi) NNE of here earthquakes near Dorado Municipio
Cataño Municipio, PR 87 km (54 mi) N of here earthquakes near Cataño Municipio
San Juan Municipio, PR 88 km (55 mi) N of here earthquakes near San Juan Municipio
Carolina Municipio, PR 91 km (57 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

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

  1. 4.0 105 km N of Suárez, Puerto Rico
  2. 3.1 56 km N of San Juan, Puerto Rico
  3. 3.3 93 km N of Brenas, Puerto Rico
  4. 3.1 81 km N of Brenas, Puerto Rico
  5. 3.7 57 km N of Brenas, Puerto Rico
  6. 3.0 66 km N of San Juan, Puerto Rico
  7. 3.1 46 km N of San Juan, Puerto Rico
  8. 3.7 107 km N of Suárez, Puerto Rico
  9. 3.2 96 km N of Brenas, Puerto Rico
  10. 3.0 96 km N of Brenas, Puerto Rico
  11. 3.0 72 km N of Tierras Nuevas Poniente, Puerto Rico
  12. 3.2 96 km N of Brenas, Puerto Rico
  13. 3.5 54 km N of Brenas, Puerto Rico
  14. 3.1 71 km N of Tierras Nuevas Poniente, Puerto Rico
  15. 3.8 100 km N of San Juan, 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 4.8 on 2017-08-18 — it released about 22 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.