QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9md

130 km NNE of San Juan, Puerto Rico

· 54 km deep · released about 10 tons of TNT

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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
54 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1307 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 17,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 760× the energy of this one
  3. Magna, Utah 2020 M 5.7 540× 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 21× 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 19.6130, -65.8076. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 3.5 137 km N of Suárez, Puerto Rico
  2. 3.9 136 km N of Suárez, Puerto Rico
  3. 3.2 127 km N of Suárez, Puerto Rico
  4. 3.8 146 km N of Suárez, Puerto Rico
  5. 3.4 144 km N of Suárez, Puerto Rico
  6. 3.8 134 km N of Su?rez, Puerto Rico
  7. 3.4 119 km N of Suárez, Puerto Rico
  8. 3.8 121 km N of Suárez, Puerto Rico
  9. 3.3 153 km N of Suárez, Puerto Rico
  10. 3.7 139 km N of Suárez, Puerto Rico
  11. 4.1 139 km N of Suárez, Puerto Rico
  12. 4.1 132 km N of Suárez, Puerto Rico
  13. 4.0 109 km N of Suárez, Puerto Rico
  14. 4.0 Puerto Rico region
  15. 4.1 141 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 4.1 on 2022-12-09 — it released about 2.5 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.