QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1Md

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

Yes. A magnitude 2.1 earthquake was recorded 115 km N of Charlotte Amalie, U.S. Virgin Islands, at 4:23 am AST on 19 August 2016 (08:23 UTC), 9.0 km deep.

· 9.0 km deep · released about 43 lb of TNT

10 km30 km60 km120 km N
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 2.1 (Md)
Depth
9.0 km below the surface
Felt
no reports yet
Nearest
Culebra Municipio, 127 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3736 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 15 km (9 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 43 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 350,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 250,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 43 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 4.0 on 2016-06-29 — about 710 times the energy of this one.

Before 2016, the USGS record lists 15 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.2 131 km NNE of Cruz Bay, U.S. Virgin Islands · 39 km ENE of this epicentre
  2. 6.1 91 km N of Charlotte Amalie, U.S. Virgin Islands · 25 km S of this epicentre
  3. 6.0 112 km N of Charlotte Amalie, U.S. Virgin Islands · 9 km WSW of this epicentre
  4. 5.7 80 km NNE of Cruz Bay, U.S. Virgin Islands · 50 km SE of this epicentre
  5. 5.6 112 km N of Charlotte Amalie, U.S. Virgin Islands · 5 km SW 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 19.3843, -64.8560. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Culebra Municipio, PR 127 km (79 mi) SSW earthquakes near Culebra Municipio
Fajardo Municipio, PR 135 km (84 mi) SW earthquakes near Fajardo Municipio
Luquillo Municipio, PR 144 km (90 mi) SW earthquakes near Luquillo Municipio
Río Grande Municipio, PR 150 km (93 mi) SW earthquakes near Río Grande Municipio
Loíza Municipio, PR 155 km (96 mi) SW earthquakes near Loíza Municipio
Canóvanas Municipio, PR 160 km (99 mi) SW earthquakes near Canóvanas Municipio

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

Aftershocks so far

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

  1. 3.5 100 km NNE of Cruz Bay, U.S. Virgin Islands
  2. 2.4 104 km NNE of Cruz Bay, U.S. Virgin Islands
  3. 3.3 112 km NNE of Cruz Bay, U.S. Virgin Islands
  4. 2.7 97 km NNE of Cruz Bay, U.S. Virgin Islands
  5. 2.6 104 km NNE of Cruz Bay, U.S. Virgin Islands
  6. 2.7 104 km NNE of Cruz Bay, U.S. Virgin Islands
  7. 4.3 101 km NNE of Cruz Bay, U.S. Virgin Islands
  8. 2.3 84 km N of Cruz Bay, U.S. Virgin Islands
  9. 2.5 91 km N of Cruz Bay, U.S. Virgin Islands
  10. 2.8 88 km N of Cruz Bay, U.S. Virgin Islands
  11. 2.6 94 km N of Cruz Bay, U.S. Virgin Islands
  12. 2.5 102 km N of Cruz Bay, U.S. Virgin Islands
  13. 3.0 96 km N of Cruz Bay, U.S. Virgin Islands
  14. 2.1 96 km N of Cruz Bay, U.S. Virgin Islands
  15. 2.8 98 km N of Cruz Bay, 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.