79 km N of Culebra, Puerto Rico

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 16 km (10 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 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.

For this area

The largest earthquake within 50 km since 2016 was M 4.4 on 2017-08-14 — about 190 times the energy of this one.

Before 2016, the USGS record lists 6 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 ENE of this epicentre Oct 11, 2008
2. 6.0 112 km N of Charlotte Amalie, U.S. Virgin Islands · 49 km NE of this epicentre Oct 17, 2001
3. 5.1 107 km N of Charlotte Amalie, U.S. Virgin Islands · 44 km NE of this epicentre May 11, 1996
4. 5.1 122 km NNE of Vieques, Puerto Rico · 44 km N of this epicentre Sep 6, 2004
5. 5.0 109 km N of Charlotte Amalie, U.S. Virgin Islands · 41 km NE of this epicentre Oct 24, 2001

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 19.0211, -65.2408. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

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

1. 3.3 75 km NNE of Luquillo, Puerto Rico 14:47 UTC
2. 3.3 66 km NNW of Charlotte Amalie, U.S. Virgin Islands 00:42 UTC
3. 3.2 62 km NNE of Culebra, Puerto Rico 00:13 UTC
4. 3.1 66 km NNW of Charlotte Amalie, U.S. Virgin Islands 21:40 UTC
5. 2.7 73 km NNW of Charlotte Amalie, U.S. Virgin Islands 06:02 UTC
6. 3.0 66 km NNW of Charlotte Amalie, U.S. Virgin Islands 03:26 UTC
7. 3.2 61 km NNW of Charlotte Amalie, U.S. Virgin Islands 03:02 UTC
8. 3.4 60 km NNE of Culebra, Puerto Rico 07:07 UTC
9. 3.7 50 km N of Charlotte Amalie, U.S. Virgin Islands 10:13 UTC
10. 3.0 103 km N of Charlotte Amalie, U.S. Virgin Islands 15:33 UTC
11. 2.6 81 km N of Cruz Bay, U.S. Virgin Islands 07:23 UTC
12. 4.2 48 km N of Charlotte Amalie, U.S. Virgin Islands 23:45 UTC
13. 2.6 99 km N of Charlotte Amalie, U.S. Virgin Islands 03:59 UTC
14. 3.4 70 km N of Charlotte Amalie, U.S. Virgin Islands 12:00 UTC
15. 3.4 52 km N of Charlotte Amalie, U.S. Virgin Islands 09:07 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 17:18 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.