QuakeIndex

Earthquake · reviewed by a seismologist

M 3.8md

130 km NNW of San Antonio, Puerto Rico

· 18 km deep · released about 6.8 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
18 km below the surface
Felt
2 reports · strongest reported intensity IV
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1786 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 2 people have reported feeling it to USGS.

How big was it?

This earthquake released about 6.8 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 25,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,100× the energy of this one
  3. Magna, Utah 2020 M 5.7 790× the energy of this one
  4. This earthquake M 3.8 about 6.8 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 14× 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 19.5945, -67.5356. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 3.6 91 km N of San Antonio, Puerto Rico
  2. 3.4 97 km NW of San Antonio, Puerto Rico
  3. 3.8 92 km NNW of San Antonio, Puerto Rico
  4. 3.7 94 km N of San Antonio, Puerto Rico
  5. 3.8 117 km NNW of San Antonio, Puerto Rico
  6. 3.2 101 km NW of San Antonio, Puerto Rico
  7. 3.4 159 km NNW of San Antonio, Puerto Rico
  8. 3.4 96 km NE of Punta Cana, Dominican Republic
  9. 3.3 90 km NNW of San Antonio, Puerto Rico
  10. 3.7 117 km NE of Punta Cana, Dominican Republic
  11. 3.3 118 km NNE of Punta Cana, Dominican Republic
  12. 4.0 120 km NNW of San Antonio, Puerto Rico
  13. 3.7 96 km NE of Punta Cana, Dominican Republic
  14. 3.7 114 km NE of Punta Cana, Dominican Republic
  15. 3.4 96 km N of Isabela, 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 4.6 on 2018-12-25 — it released about 18 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.