QuakeIndex

Earthquake · reviewed by a seismologist

M 4.0ml

121 km N of San Juan, Puerto Rico

· 14 km deep · released about 15 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 4.0 (ml)
Depth
14 km below the surface
Felt
no reports yet
Nearest
Isabela Municipio, 148 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2573 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

How big was it?

This earthquake released about 15 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 11,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 500× the energy of this one
  3. Magna, Utah 2020 M 5.7 350× the energy of this one
  4. This earthquake M 4.0 about 15 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 32× 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 19.5591, -66.1913. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Isabela Municipio, PR 148 km (92 mi) NE of here earthquakes near Isabela Municipio

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

Aftershocks so far

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

  1. 1.8 77 km N of San Juan, Puerto Rico
  2. 1.9 77 km N of San Juan, Puerto Rico
  3. 2.8 94 km N of San Juan, Puerto Rico
  4. 2.6 76 km N of San Juan, Puerto Rico
  5. 2.5 76 km N of San Juan, Puerto Rico
  6. 2.1 79 km N of San Juan, Puerto Rico
  7. 2.5 78 km N of San Juan, Puerto Rico
  8. 2.4 85 km N of Brenas, Puerto Rico
  9. 2.9 105 km N of San Juan, Puerto Rico
  10. 3.0 101 km N of Brenas, Puerto Rico
  11. 2.9 102 km N of Brenas, Puerto Rico
  12. 2.6 100 km N of Brenas, Puerto Rico
  13. 2.9 127 km N of Brenas, Puerto Rico
  14. 3.0 122 km N of Brenas, Puerto Rico
  15. 2.9 97 km N of Brenas, 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 4 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.