QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7Md

116 km NNW of Charlotte Amalie, U.S. Virgin Islands

Yes. A magnitude 2.7 earthquake was recorded 116 km NNW of Charlotte Amalie, U.S. Virgin Islands, at 5:47 am AST on 21 October 2016 (09:47 UTC), 9.0 km deep.

· 9.0 km deep · released about 340 lb of TNT

10 km30 km60 km120 km N Fajardo Municipio 115 kmCulebra Municipio 115 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 2.7 (Md)
Depth
9.0 km below the surface
Felt
no reports yet
Nearest
Fajardo Municipio, 115 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3583 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 23 km (14 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 340 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 45,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 32,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.8× the energy of this one
  4. This earthquake M 2.7 about 340 lb of TNT

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 250 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 · 46 km ESE of this epicentre
  2. 6.0 112 km N of Charlotte Amalie, U.S. Virgin Islands · 31 km E of this epicentre
  3. 5.6 112 km N of Charlotte Amalie, U.S. Virgin Islands · 35 km E of this epicentre
  4. 5.1 107 km N of Charlotte Amalie, U.S. Virgin Islands · 28 km E of this epicentre
  5. 5.1 122 km NNE of Vieques, Puerto Rico · 11 km WNW 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 19.3570, -65.2236. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Fajardo Municipio, PR 115 km (71 mi) SSW earthquakes near Fajardo Municipio
Culebra Municipio, PR 115 km (71 mi) S earthquakes near Culebra Municipio
Luquillo Municipio, PR 121 km (75 mi) SSW earthquakes near Luquillo Municipio
Río Grande Municipio, PR 125 km (77 mi) SSW earthquakes near Río Grande Municipio
Loíza Municipio, PR 126 km (79 mi) SW earthquakes near Loíza Municipio
Carolina Municipio, PR 132 km (82 mi) SW earthquakes near Carolina Municipio

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

Aftershocks so far

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

  1. 3.4 85 km N of Culebra, Puerto Rico
  2. 3.9 118 km NNE of Vieques, Puerto Rico
  3. 3.4 129 km NNE of Suárez, Puerto Rico
  4. 2.9 105 km NNE of Vieques, Puerto Rico
  5. 2.9 79 km N of Culebra, Puerto Rico
  6. 2.7 94 km NNW of Charlotte Amalie, U.S. Virgin Islands
  7. 3.6 121 km N of Charlotte Amalie, U.S. Virgin Islands
  8. 2.4 126 km NNE of Vieques, Puerto Rico
  9. 3.1 Virgin Islands
  10. 2.0 75 km N of Charlotte Amalie, U.S. Virgin Islands
  11. 3.1 145 km NNW of Charlotte Amalie, U.S. Virgin Islands
  12. 2.5 73 km N of Culebra, Puerto Rico
  13. 3.1 102 km N of Charlotte Amalie, U.S. Virgin Islands
  14. 3.2 120 km NNW of Charlotte Amalie, U.S. Virgin Islands
  15. 3.0 68 km NNW of Charlotte Amalie, U.S. Virgin Islands

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.