QuakeIndex

Earthquake · reviewed by a seismologist

M 3.6md

110 km N of Charlotte Amalie, U.S. Virgin Islands

Yes. A magnitude 3.6 earthquake was recorded 110 km N of Charlotte Amalie, U.S. Virgin Islands, at 5:52 pm AST on 11 March 2018 (21:52 UTC), 65 km deep.

· 65 km deep · released about 4.1 tons of TNT

10 km30 km60 km120 km N Culebra Municipio 116 kmFajardo 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 3.6 (md)
Depth
65 km below the surface
Felt
no reports yet
Nearest
Culebra Municipio, 116 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3079 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 28 km (17 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 4.1 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.6 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 42,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,900× the energy of this one
  3. Magna, Utah 2020 M 5.7 1,300× the energy of this one
  4. This earthquake M 3.6 about 4.1 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 8.5× 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 4.5 on 2018-02-09 — about 21 times the energy of this one.

Before 2016, the USGS record lists 11 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.1 91 km N of Charlotte Amalie, U.S. Virgin Islands · 30 km SE of this epicentre
  2. 6.0 112 km N of Charlotte Amalie, U.S. Virgin Islands · 13 km E of this epicentre
  3. 5.6 112 km N of Charlotte Amalie, U.S. Virgin Islands · 17 km E of this epicentre
  4. 5.3 97 km N of Cruz Bay, U.S. Virgin Islands · 45 km ESE of this epicentre
  5. 5.2 99 km N of Cruz Bay, U.S. Virgin Islands · 41 km ESE 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 19.3373, -65.0500. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Culebra Municipio, PR 116 km (72 mi) SSW earthquakes near Culebra Municipio
Fajardo Municipio, PR 120 km (75 mi) SSW earthquakes near Fajardo Municipio
Luquillo Municipio, PR 128 km (80 mi) SSW earthquakes near Luquillo Municipio
Río Grande Municipio, PR 133 km (82 mi) SW earthquakes near Río Grande Municipio
Loíza Municipio, PR 137 km (85 mi) SW earthquakes near Loíza Municipio
Carolina Municipio, PR 142 km (88 mi) SW earthquakes near Carolina Municipio

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

Aftershocks so far

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

  1. 3.4 103 km N of Charlotte Amalie, U.S. Virgin Islands
  2. 3.4 116 km N of Charlotte Amalie, U.S. Virgin Islands
  3. 3.3 86 km N of Cruz Bay, 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. 2.8 82 km NNE of Luquillo, Puerto Rico
  9. 3.0 79 km N of Culebra, Puerto Rico
  10. 3.3 79 km N of Culebra, Puerto Rico
  11. 3.3 115 km N of Cruz Bay, U.S. Virgin Islands
  12. 3.4 90 km N of Cruz Bay, U.S. Virgin Islands
  13. 3.4 82 km NNE of Luquillo, Puerto Rico
  14. 3.3 77 km N of Culebra, Puerto Rico
  15. 2.6 78 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.