QuakeIndex

Earthquake · reviewed by a seismologist

M 4.5mb

109 km N of Culebra, Puerto Rico

Yes. A magnitude 4.5 earthquake was recorded 109 km N of Culebra, Puerto Rico, at 1:54 pm AST on 6 March 2018 (17:54 UTC), 42 km deep. 3 people have reported feeling it to USGS.

· 42 km deep · released about 85 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Fajardo Municipio 106 kmCulebra Municipio 108 kmLuquillo Municipio 113 kmRío Grande Municipio 116 kmLoíza Municipio 118 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 4.5 (mb)
Depth
42 km below the surface
Felt
3 reports · strongest reported intensity III
Nearest
Fajardo Municipio, 106 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1557 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 133 km (83 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 85 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.5 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 2,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 89× the energy of this one
  3. Magna, Utah 2020 M 5.7 63× the energy of this one
  4. This earthquake M 4.5 about 85 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 180× 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

Tied for the largest within 50 km (31 mi) since 2016, with M 4.5 on 2018-02-09.

Before 2016, the USGS record lists 10 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.1 91 km N of Charlotte Amalie, U.S. Virgin Islands · 48 km ESE of this epicentre
  2. 6.0 112 km N of Charlotte Amalie, U.S. Virgin Islands · 35 km E of this epicentre
  3. 5.6 112 km N of Charlotte Amalie, U.S. Virgin Islands · 40 km E of this epicentre
  4. 5.1 107 km N of Charlotte Amalie, U.S. Virgin Islands · 32 km E of this epicentre
  5. 5.1 122 km NNE of Vieques, Puerto Rico · 14 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 19.2934, -65.2640. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Fajardo Municipio, PR 106 km (66 mi) SSW earthquakes near Fajardo Municipio
Culebra Municipio, PR 108 km (67 mi) S earthquakes near Culebra Municipio
Luquillo Municipio, PR 113 km (70 mi) SSW earthquakes near Luquillo Municipio
Río Grande Municipio, PR 116 km (72 mi) SSW earthquakes near Río Grande Municipio
Loíza Municipio, PR 118 km (73 mi) SW earthquakes near Loíza Municipio
Ceiba Municipio, PR 122 km (76 mi) SSW earthquakes near Ceiba Municipio

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

Aftershocks so far

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

  1. 2.9 135 km NNE of Vieques, Puerto Rico
  2. 3.4 103 km N of Charlotte Amalie, U.S. Virgin Islands
  3. 3.4 116 km N of Charlotte Amalie, U.S. Virgin Islands
  4. 3.4 74 km N of Charlotte Amalie, U.S. Virgin Islands
  5. 3.3 110 km N of Charlotte Amalie, U.S. Virgin Islands
  6. 3.3 71 km N of Charlotte Amalie, U.S. Virgin Islands
  7. 2.7 81 km N of Culebra, Puerto Rico
  8. 2.6 76 km NNE of Luquillo, Puerto Rico
  9. 3.1 68 km NNE of Luquillo, Puerto Rico
  10. 2.8 82 km NNE of Luquillo, Puerto Rico
  11. 3.0 79 km N of Culebra, Puerto Rico
  12. 3.3 79 km N of Culebra, Puerto Rico
  13. 3.1 72 km N of Culebra, Puerto Rico
  14. 2.8 61 km NNW of Charlotte Amalie, U.S. Virgin Islands
  15. 3.1 66 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.