QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3md

65 km NNE of Cruz Bay, U.S. Virgin Islands

· 9.6 km deep · released about 1.5 tons of TNT

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10 km30 km60 km120 km N Culebra Municipio 104 km
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
Magnitude
M 3.3 (md)
Depth
9.6 km below the surface
Felt
no reports yet
Nearest
Culebra Municipio, 104 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1 hour ago

A magnitude 3.3 earthquake was recorded 65 km NNE of Cruz Bay, U.S. Virgin Islands at 03:08 UTC on 2026-10-04. 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 1.5 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 110,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 5,100× the energy of this one
  3. Magna, Utah 2020 M 5.7 3,600× the energy of this one
  4. This earthquake M 3.3 about 1.5 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 3.1× 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 5.7 on 2023-12-09 — about 3,600 times the energy of this one.

Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.9 68 km N of Cruz Bay, U.S. Virgin Islands · 26 km WNW of this epicentre
  2. 5.9 65 km NNE of Cruz Bay, U.S. Virgin Islands · 11 km WNW of this epicentre
  3. 5.7 80 km NNE of Cruz Bay, U.S. Virgin Islands · 22 km NNW of this epicentre
  4. 5.3 78 km NNE of Cruz Bay, U.S. Virgin Islands · 25 km NW of this epicentre
  5. 5.3 97 km N of Cruz Bay, U.S. Virgin Islands · 43 km NNW of this epicentre

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 18.8438, -64.4870. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Culebra Municipio, PR 104 km (65 mi) WSW earthquakes near Culebra Municipio
Fajardo Municipio, PR 127 km (79 mi) WSW earthquakes near Fajardo Municipio
Vieques Municipio, PR 128 km (79 mi) SW earthquakes near Vieques Municipio
Ceiba Municipio, PR 136 km (85 mi) WSW earthquakes near Ceiba Municipio

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

Aftershocks so far

1 earthquake has been recorded within 50 km since this one.

  1. 3.3 64 km NNE of Cruz Bay, U.S. Virgin Islands

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

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.