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

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 57 km (35 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 2.2 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.

1. Northridge, California 1994 M 6.7 78,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 3,500× the energy of this one
3. Magna, Utah 2020 M 5.7 2,500× the energy of this one
4. This earthquake M 3.4 about 2.2 tons of TNT
5. Around the size people start to feel M 3.0 this one released 4.6× 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 4.7 on 2017-07-22 — about 78 times the energy of this one.

Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.

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 19.9531, -64.9560. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 3.5 138 km N of Charlotte Amalie, U.S. Virgin Islands 23:20 UTC
2. 2.8 137 km N of Cruz Bay, U.S. Virgin Islands 11:12 UTC
3. 3.4 156 km N of Charlotte Amalie, U.S. Virgin Islands 14:26 UTC
4. 2.8 163 km N of Charlotte Amalie, U.S. Virgin Islands 05:48 UTC
5. 3.2 173 km N of Charlotte Amalie, U.S. Virgin Islands 04:18 UTC
6. 3.8 136 km N of Charlotte Amalie, U.S. Virgin Islands 07:21 UTC
7. 3.2 147 km N of Charlotte Amalie, U.S. Virgin Islands 04:35 UTC
8. 3.4 132 km N of Charlotte Amalie, U.S. Virgin Islands 01:52 UTC
9. 3.2 141 km NNW of Charlotte Amalie, U.S. Virgin Islands 18:05 UTC
10. 3.4 153 km NNE of Vieques, Puerto Rico 04:11 UTC
11. 3.3 133 km N of Charlotte Amalie, U.S. Virgin Islands 06:02 UTC
12. 3.1 133 km N of Charlotte Amalie, U.S. Virgin Islands 06:00 UTC
13. 3.2 149 km NNE of Vieques, Puerto Rico 00:38 UTC
14. 3.2 Puerto Rico region 23:56 UTC
15. 3.4 160 km NNE of Vieques, Puerto Rico 08:17 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 20:08 UTC. 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.