QuakeIndex

Earthquake · reviewed by a seismologist

M 3.8md

127 km N of Suárez, Puerto Rico

Yes. A magnitude 3.8 earthquake was recorded 127 km N of Suárez, Puerto Rico, at 12:37 pm AST on 31 March 2024 (16:37 UTC), 102 km deep.

· 102 km deep · released about 8.7 tons of TNT

10 km30 km60 km120 km N
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 3.8 (md)
Depth
102 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 955 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

How big was it?

This earthquake released about 8.7 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.8 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 19,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 870× the energy of this one
  3. Magna, Utah 2020 M 5.7 620× the energy of this one
  4. This earthquake M 3.8 about 8.7 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 18× 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.

For this area

The largest earthquake within 50 km since 2016 was M 4.4 on 2023-02-28 — about 7.9 times the energy of this one.

Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:

  1. 5.1 122 km NNE of Vieques, Puerto Rico · 41 km ESE of this epicentre
  2. 5.1 92 km N of Suárez, Puerto Rico · 35 km S of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 19.5695, -65.6631. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 3.2 136 km NNE of Vieques, Puerto Rico
  2. 3.2 134 km NNE of Vieques, Puerto Rico
  3. 3.2 140 km NNE of Vieques, Puerto Rico
  4. 4.7 137 km N of Culebra, Puerto Rico
  5. 3.6 132 km NNE of Vieques, Puerto Rico
  6. 3.5 136 km NNE of Vieques, Puerto Rico
  7. 3.8 139 km NNW of Charlotte Amalie, U.S. Virgin Islands
  8. 3.3 139 km NNE of Vieques, Puerto Rico
  9. 3.8 135 km NNE of Vieques, Puerto Rico
  10. 3.5 131 km NNE of Vieques, Puerto Rico
  11. 3.7 123 km NNE of Vieques, Puerto Rico
  12. 3.8 139 km NNE of Vieques, Puerto Rico
  13. 3.4 145 km NNE of Vieques, Puerto Rico
  14. 3.6 133 km N of Culebra, Puerto Rico
  15. 3.7 128 km N of Culebra, 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.

On USGS

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