QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9md

118 km N of Brenas, Puerto Rico

· 28 km deep · released about 10 tons of TNT

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10 km30 km60 km120 km N Dorado Municipio 118 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
28 km below the surface
Felt
no reports yet
Nearest
Dorado Municipio, 118 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1156 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 10 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 5.8 730× the energy of this one
  3. Magna, Utah 2020 M 5.7 520× the energy of this one
  4. This earthquake M 3.9 about 10 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 19.5360, -66.2878. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Dorado Municipio, PR 118 km (73 mi) N of here earthquakes near Dorado Municipio
Barceloneta Municipio, PR 122 km (76 mi) NNE of here earthquakes near Barceloneta Municipio
Quebradillas Municipio, PR 137 km (85 mi) NNE of here earthquakes near Quebradillas Municipio
Isabela Municipio, PR 140 km (87 mi) NNE of here earthquakes near Isabela Municipio
Aguadilla Municipio, PR 148 km (92 mi) NE of here earthquakes near Aguadilla Municipio

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

Aftershocks so far

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

  1. 3.2 89 km N of Brenas, Puerto Rico
  2. 3.9 98 km N of Brenas, Puerto Rico
  3. 3.9 111 km N of Brenas, Puerto Rico
  4. 3.4 104 km NNE of San Juan, Puerto Rico
  5. 3.5 124 km N of San Juan, Puerto Rico
  6. 3.1 Puerto Rico region
  7. 3.1 Puerto Rico region
  8. 4.0 111 km N of San Juan, Puerto Rico
  9. 3.8 115 km N of San Juan, Puerto Rico
  10. 3.7 120 km N of San Juan, Puerto Rico
  11. 3.8 127 km N of San Juan, Puerto Rico
  12. 3.4 104 km N of San Juan, Puerto Rico
  13. 3.9 144 km N of San Juan, Puerto Rico
  14. 3.4 125 km N of San Juan, Puerto Rico
  15. 3.8 158 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 4.4 on 2016-10-23 — it released about 5.8 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.