113 km N of Cruz Bay, U.S. Virgin Islands

2021-10-31 07:14 UTC · 18 km deep · released about 15 tons of TNT

Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.

When: 2021-10-31 07:14 UTC
Magnitude: M 4.0 (md)
Depth: 18 km below the surface
Felt: no reports yet
Nearest: Culebra Municipio, 130 km SSW
Status: Reviewed by a seismologist

USGS · last changed by USGS 1717 days ago · we first saw it 1717 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

How big was it?

This earthquake released about 15 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.0 would have released about 32 times as much.

Northridge, California 1994 M 6.7 11,000× the energy of this one
Mineral, Virginia 2011 M 5.8 500× the energy of this one
Magna, Utah 2020 M 5.7 350× the energy of this one
This earthquake M 4.0 about 15 tons of TNT
Around the size people start to feel M 3.0 this one released 32× 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.

Where

Map loads when it scrolls into view

Epicentre 19.3558, -64.7218. Map © OpenStreetMap contributors.

Nearby places

Place	Distance	Direction
Culebra Municipio, PR	130 km (81 mi)	NNE of here	earthquakes near Culebra Municipio
Fajardo Municipio, PR	141 km (88 mi)	NE of here	earthquakes near Fajardo Municipio
Luquillo Municipio, PR	151 km (94 mi)	NE of here	earthquakes near Luquillo Municipio
Río Grande Municipio, PR	157 km (98 mi)	NE of here	earthquakes near Río Grande Municipio

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

Aftershocks so far

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

4.0 91 km NNE of Cruz Bay, U.S. Virgin Islands 07:40 UTC
3.9 106 km N of Cruz Bay, U.S. Virgin Islands 14:35 UTC
4.1 104 km N of Charlotte Amalie, U.S. Virgin Islands 23:50 UTC
3.8 114 km NNE of Cruz Bay, U.S. Virgin Islands 23:38 UTC
3.7 105 km NNW of Charlotte Amalie, U.S. Virgin Islands 12:32 UTC
3.4 103 km NNW of Charlotte Amalie, U.S. Virgin Islands 12:00 UTC
3.7 99 km N of Charlotte Amalie, U.S. Virgin Islands 07:13 UTC
3.8 138 km N of Cruz Bay, U.S. Virgin Islands 04:16 UTC
3.6 79 km NNE of Cruz Bay, U.S. Virgin Islands 13:16 UTC
3.8 79 km NNE of Cruz Bay, U.S. Virgin Islands 13:04 UTC
4.0 110 km N of Cruz Bay, U.S. Virgin Islands 05:09 UTC
4.2 140 km N of Cruz Bay, U.S. Virgin Islands 16:20 UTC
3.7 87 km N of Charlotte Amalie, U.S. Virgin Islands 14:00 UTC
3.8 83 km N of Cruz Bay, U.S. Virgin Islands 12:03 UTC
4.0 120 km N of Charlotte Amalie, U.S. Virgin Islands 06:40 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 16:50 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 5.0 on 2021-02-06 — it released about 31 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.