QuakeIndex

Earthquake · reviewed by a seismologist

M 3.4md

Puerto Rico region

Yes. A magnitude 3.4 earthquake was recorded in the Puerto Rico region, 91 km (57 mi) NE of San Juan, PR, at 3:53 am AST on 7 January 2023 (07:53 UTC), 42 km deep. 1 person has reported feeling it to USGS.

91 km (57 mi) NE of San Juan, PR

· 42 km deep · released about 2.1 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Fajardo Municipio 71 kmLuquillo Municipio 76 kmRío Grande Municipio 78 kmCulebra Municipio 79 kmLoíza Municipio 80 kmCarolina Municipio 86 kmCeiba Municipio 86 kmCanóvanas Municipio 87 kmSan Juan Municipio 90 km
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 3.4 (md)
Depth
42 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Fajardo Municipio, 71 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1405 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, people at rest would likely notice it out to about 42 km (26 mi) from the epicentre. 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 2.1 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.4 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 80,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 3,600× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,500× the energy of this one
  4. This earthquake M 3.4 about 2.1 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 4.4× 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 in our catalogue was M 4.8 on 2021-03-09 — about 110 times the energy of this one.

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 19.0137, -65.4813. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Fajardo Municipio, PR 71 km (44 mi) S earthquakes near Fajardo Municipio
Luquillo Municipio, PR 76 km (47 mi) SSW earthquakes near Luquillo Municipio
Río Grande Municipio, PR 78 km (49 mi) SSW earthquakes near Río Grande Municipio
Culebra Municipio, PR 79 km (49 mi) SSE earthquakes near Culebra Municipio
Loíza Municipio, PR 80 km (50 mi) SW earthquakes near Loíza Municipio
Carolina Municipio, PR 86 km (53 mi) SW earthquakes near Carolina Municipio

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

Aftershocks so far

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

  1. 3.2 81 km N of Culebra, Puerto Rico
  2. 3.2 Puerto Rico region
  3. 3.1 71 km N of Charlotte Amalie, U.S. Virgin Islands
  4. 3.3 82 km NNE of Suárez, Puerto Rico
  5. 3.1 68 km NNE of Suárez, Puerto Rico
  6. 3.3 86 km NNE of Suárez, Puerto Rico
  7. 3.3 Puerto Rico region
  8. 3.4 79 km NNW of Charlotte Amalie, U.S. Virgin Islands
  9. 3.4 72 km N of Charlotte Amalie, U.S. Virgin Islands
  10. 3.7 61 km N of Charlotte Amalie, U.S. Virgin Islands
  11. 3.8 Puerto Rico region
  12. 3.7 Puerto Rico region
  13. 3.4 120 km NNE of Vieques, Puerto Rico
  14. 3.4 Puerto Rico region
  15. 2.9 49 km NE of Luquillo, 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.