QuakeIndex

Earthquake · reviewed by a seismologist

M 3.4Md

102 km N of Culebra, Puerto Rico

Yes. A magnitude 3.4 earthquake was recorded 102 km N of Culebra, Puerto Rico, at 11:55 pm AST on 9 February 2017 (03:55 UTC), 78 km deep.

· 78 km deep · released about 1.9 tons of TNT

10 km30 km60 km120 km N Fajardo Municipio 100 kmCulebra Municipio 100 kmLuquillo Municipio 107 kmRío Grande Municipio 111 kmLoíza Municipio 114 kmCeiba Municipio 115 kmCarolina Municipio 120 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
78 km below the surface
Felt
no reports yet
Nearest
Fajardo Municipio, 100 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3475 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 1.9 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 89,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 4,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,800× the energy of this one
  4. This earthquake M 3.4 about 1.9 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 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 since 2016 was M 4.3 on 2016-09-04 — about 22 times the energy of this one.

Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.1 91 km N of Charlotte Amalie, U.S. Virgin Islands · 44 km E of this epicentre
  2. 6.0 112 km N of Charlotte Amalie, U.S. Virgin Islands · 36 km ENE of this epicentre
  3. 5.6 112 km N of Charlotte Amalie, U.S. Virgin Islands · 40 km ENE of this epicentre
  4. 5.1 107 km N of Charlotte Amalie, U.S. Virgin Islands · 32 km ENE of this epicentre
  5. 5.1 122 km NNE of Vieques, Puerto Rico · 22 km NNW 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 19.2240, -65.2433. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Fajardo Municipio, PR 100 km (62 mi) SSW earthquakes near Fajardo Municipio
Culebra Municipio, PR 100 km (62 mi) S earthquakes near Culebra Municipio
Luquillo Municipio, PR 107 km (67 mi) SSW earthquakes near Luquillo Municipio
Río Grande Municipio, PR 111 km (69 mi) SSW earthquakes near Río Grande Municipio
Loíza Municipio, PR 114 km (71 mi) SW earthquakes near Loíza Municipio
Ceiba Municipio, PR 115 km (71 mi) SSW earthquakes near Ceiba Municipio

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

Aftershocks so far

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

  1. 3.1 96 km NNE of Vieques, Puerto Rico
  2. 3.4 96 km N of Charlotte Amalie, U.S. Virgin Islands
  3. 3.4 101 km N of Charlotte Amalie, U.S. Virgin Islands
  4. 3.1 72 km N of Charlotte Amalie, U.S. Virgin Islands
  5. 3.3 96 km NNE of Luquillo, Puerto Rico
  6. 2.7 89 km N of Charlotte Amalie, U.S. Virgin Islands
  7. 2.8 130 km NNW of Charlotte Amalie, U.S. Virgin Islands
  8. 3.4 89 km N of Charlotte Amalie, U.S. Virgin Islands
  9. 2.8 75 km N of Culebra, Puerto Rico
  10. 2.9 81 km NNW of Charlotte Amalie, U.S. Virgin Islands
  11. 3.4 Puerto Rico region
  12. 2.7 80 km NNE of Vieques, Puerto Rico
  13. 3.2 84 km NNE of Suárez, Puerto Rico
  14. 3.0 70 km N of Charlotte Amalie, U.S. Virgin Islands
  15. 2.9 60 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.