QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9md

140 km N of Suárez, Puerto Rico

· 41 km deep · released about 11 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
41 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1345 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 15,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 660× the energy of this one
  3. Magna, Utah 2020 M 5.7 470× 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 24× 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 19.6928, -65.7233. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 4.0 128 km N of Suárez, Puerto Rico
  2. 3.9 124 km N of Suárez, Puerto Rico
  3. 3.6 118 km N of Suárez, Puerto Rico
  4. 3.4 132 km N of Suárez, Puerto Rico
  5. 3.7 113 km N of Suárez, Puerto Rico
  6. 3.4 Puerto Rico region
  7. 3.9 138 km N of Suárez, Puerto Rico
  8. 3.6 137 km NNE of Vieques, Puerto Rico
  9. 3.4 Puerto Rico region
  10. 3.4 145 km NNE of Vieques, Puerto Rico
  11. 3.7 133 km NNE of Vieques, Puerto Rico
  12. 3.4 146 km NNE of Vieques, Puerto Rico
  13. 3.9 134 km NNE of Vieques, Puerto Rico
  14. 4.0 120 km NNE of Vieques, Puerto Rico
  15. 3.9 Puerto Rico region

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.

On USGS

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