135 km NNE of Vieques, Puerto Rico

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

How big was it?

This earthquake released about 650 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 23,000× the energy of this one
2. Magna, Utah 2020 M 5.7 16,000× the energy of this one
3. Around the size people start to feel M 3.0 1.5× the energy of this one
4. This earthquake M 2.9 about 650 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.

Where

Epicentre 19.5731, -65.3883. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 3.4 117 km N of Charlotte Amalie, U.S. Virgin Islands 14:46 UTC
2. 3.5 126 km NNE of Suárez, Puerto Rico 02:55 UTC
3. 2.6 134 km NNE of Vieques, Puerto Rico 00:43 UTC
4. 3.2 148 km N of Charlotte Amalie, U.S. Virgin Islands 00:20 UTC
5. 4.9 143 km N of Charlotte Amalie, U.S. Virgin Islands 00:10 UTC
6. 2.9 116 km NNE of Vieques, Puerto Rico 08:05 UTC
7. 3.3 117 km NNE of Suárez, Puerto Rico 20:18 UTC
8. 3.1 116 km NNE of Vieques, Puerto Rico 19:20 UTC
9. 3.1 108 km NNW of Charlotte Amalie, U.S. Virgin Islands 16:44 UTC
10. 3.4 128 km NNE of Vieques, Puerto Rico 01:42 UTC
11. 2.5 110 km NNW of Charlotte Amalie, U.S. Virgin Islands 08:10 UTC
12. 3.3 158 km NNE of Suárez, Puerto Rico 08:51 UTC
13. 3.2 125 km N of Culebra, Puerto Rico 03:52 UTC
14. 3.4 135 km NNE of Suárez, Puerto Rico 23:16 UTC
15. 2.6 151 km N of Charlotte Amalie, U.S. Virgin Islands 06:14 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 13:19 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

For this area

The largest earthquake within 50 km in our catalogue was M 4.5 on 2018-03-06 — it released about 260 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

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.