160 km N of Cruz Bay, 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 it was probably too small to be felt, even directly above it. 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 860 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 390,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 18,000× the energy of this one
3. Magna, Utah 2020 M 5.7 12,000× the energy of this one
4. This earthquake M 3.0 about 860 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 5.0 on 2019-10-06 — about 970 times the energy of this one.

Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:

1. 6.2 131 km NNE of Cruz Bay, U.S. Virgin Islands · 38 km SSE of this epicentre Sep 6, 1919
2. 5.0 122 km N of Charlotte Amalie, U.S. Virgin Islands · 44 km SSW of this epicentre Mar 19, 1984
3. 5.0 116 km N of Charlotte Amalie, U.S. Virgin Islands · 47 km SSW of this epicentre Apr 5, 1984
4. 5.0 127 km NNE of Cruz Bay, U.S. Virgin Islands · 41 km SSE of this epicentre Jan 13, 1993

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 19.7811, -64.6978. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 3.6 139 km N of Cruz Bay, U.S. Virgin Islands 21:41 UTC
2. 3.4 175 km N of Charlotte Amalie, U.S. Virgin Islands 03:02 UTC
3. 3.9 150 km N of Cruz Bay, U.S. Virgin Islands 08:57 UTC
4. 3.6 144 km N of Charlotte Amalie, U.S. Virgin Islands 09:06 UTC
5. 3.8 162 km N of Cruz Bay, U.S. Virgin Islands 21:06 UTC
6. 3.1 118 km N of Charlotte Amalie, U.S. Virgin Islands 11:18 UTC
7. 3.9 119 km N of Charlotte Amalie, U.S. Virgin Islands 08:20 UTC
8. 3.9 139 km N of Cruz Bay, U.S. Virgin Islands 04:01 UTC
9. 3.0 155 km NNE of Cruz Bay, U.S. Virgin Islands 12:10 UTC
10. 3.7 113 km N of Charlotte Amalie, U.S. Virgin Islands 10:39 UTC
11. 3.5 160 km NNE of Cruz Bay, U.S. Virgin Islands 20:43 UTC
12. 3.6 120 km N of Cruz Bay, U.S. Virgin Islands 20:07 UTC
13. 3.7 161 km N of Cruz Bay, U.S. Virgin Islands 10:17 UTC
14. 3.7 142 km NNE of Cruz Bay, U.S. Virgin Islands 06:59 UTC
15. 3.7 162 km N of Cruz Bay, U.S. Virgin Islands 06:10 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 04:21 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.