Earthquake · reviewed by a seismologist
M 3.4md
51 km N of Charlotte Amalie, U.S. Virgin Islands
Yes. A magnitude 3.4 earthquake was recorded 51 km N of Charlotte Amalie, U.S. Virgin Islands, at 5:55 pm AST on 19 December 2021 (21:55 UTC), 59 km deep.
- When
- Magnitude
- M 3.4 (md)
- Depth
- 59 km below the surface
- Felt
- no reports yet
- Nearest
- Culebra Municipio, 65 km SW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1788 days ago
Earthquake alerts for Culebra, PR
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Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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 7 km (4 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 2.1 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.
- Northridge, California 1994 M 6.7 80,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 3,600× the energy of this one
- Magna, Utah 2020 M 5.7 2,500× the energy of this one
- This earthquake M 3.4 about 2.1 tons of TNT
- Around the size people start to feel M 3.0 this one released 4.4× 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 5.0 on 2021-02-06 — about 220 times the energy of this one.
Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:
- 6.1 91 km N of Charlotte Amalie, U.S. Virgin Islands · 41 km NNE of this epicentre
- 5.9 68 km N of Cruz Bay, U.S. Virgin Islands · 30 km ENE of this epicentre
- 5.9 65 km NNE of Cruz Bay, U.S. Virgin Islands · 40 km ENE of this epicentre
- 5.7 80 km NNE of Cruz Bay, U.S. Virgin Islands · 46 km ENE of this epicentre
- 5.3 78 km NNE of Cruz Bay, U.S. Virgin Islands · 41 km NE 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 18.8060, -64.9515. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Culebra Municipio, PR | 65 km (41 mi) | SW | earthquakes near Culebra Municipio |
| Fajardo Municipio, PR | 82 km (51 mi) | SW | earthquakes near Fajardo Municipio |
| Vieques Municipio, PR | 91 km (57 mi) | SW | earthquakes near Vieques Municipio |
| Ceiba Municipio, PR | 94 km (58 mi) | SW | earthquakes near Ceiba Municipio |
| Luquillo Municipio, PR | 94 km (58 mi) | WSW | earthquakes near Luquillo Municipio |
| Río Grande Municipio, PR | 101 km (63 mi) | WSW | earthquakes near Río Grande Municipio |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
40 earthquakes have been recorded within 50 km since this one.
- 3.2 62 km NNW of Charlotte Amalie, U.S. Virgin Islands
- 3.9 74 km N of Culebra, Puerto Rico
- 3.5 61 km N of Culebra, Puerto Rico
- 3.2 50 km N of Culebra, Puerto Rico
- 3.3 60 km N of Culebra, Puerto Rico
- 3.2 73 km NNW of Charlotte Amalie, U.S. Virgin Islands
- 3.4 37 km NW of Charlotte Amalie, U.S. Virgin Islands
- 3.3 18 km NW of Charlotte Amalie, U.S. Virgin Islands
- 3.4 50 km NNW of Charlotte Amalie, U.S. Virgin Islands
- 3.4 67 km N of Culebra, Puerto Rico
- 3.0 38 km NNE of Culebra, Puerto Rico
- 3.5 72 km NNW of Charlotte Amalie, U.S. Virgin Islands
- 3.6 83 km N of Culebra, Puerto Rico
- 3.7 79 km N of Culebra, Puerto Rico
- 4.1 84 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.