M3.3 earthquake 55 km N of Charlotte Amalie, Saint Thomas Island, U.S. Virgin Islands

Name: M3.3 earthquake 55 km N of Charlotte Amalie, Saint Thomas Island, U.S. Virgin Islands
Start: 2026-08-30T15:33:01.080Z
End: 2026-08-30T15:33:01.080Z
Location: 55 km N of Charlotte Amalie, Saint Thomas Island, U.S. Virgin Islands

A magnitude 3.3 earthquake struck 55 km N of Charlotte Amalie, Saint Thomas Island, U.S. Virgin Islands at 11:33 local time (15:33 UTC) on 30 Aug 2026, at a depth of 54 km, according to USGS.

Data: USGS · updated 2026-09-11 19:12 UTC · reviewed

Magnitude: 3.3minor
duration magnitude (md)
Depth: 54.3 km
Status: Reviewed
Origin time: 2026-08-30 15:33:01 UTC; Local: 30 Aug 2026, 11:33:01 (America/St Thomas)
Epicentre: 18.822° N, 65.028° W

Circles show this event and others within 30 km from 7 days before to 30 days after. Lines: plate boundaries and GEM active faults. Open on the live map

Nearby places

Distance and estimated shaking at nearby places
Place	Distance	Est. shaking
Charlotte AmalieSaint Thomas Island, U.S. Virgin Islands · pop. 20,000	55 km	INot felt
TutuSaint Thomas Island, U.S. Virgin Islands · pop. 5,519	56 km	INot felt
FajardoPuerto Rico · pop. 32,124	85 km	INot felt
CarolinaPuerto Rico · pop. 170,404	110 km	INot felt
HumacaoPuerto Rico · pop. 20,387	113 km	INot felt
San JuanPuerto Rico · pop. 418,140	121 km	INot felt

Shaking is an estimate from the intensity prediction equation of Allen, Wald & Worden (2012), not an observation. Local ground and buildings can change it by a level or more.

Every agency's solution

Agencies locate earthquakes with their own stations and methods, so their numbers differ. We match reports of the same event by time, distance and magnitude and show them side by side. The headline uses USGS · PR, which has been reviewed by an analyst.

Agency	Magnitude	Depth	Epicentre	Time offset	Status
USGS · PRheadlinePuerto Rico Seismic Network via U.S. Geological Survey	3.3 md	54.3 km	18.82° N, 65.03° W	–	Reviewed

How big was it?

Often felt by people at rest close to the epicentre, rarely causes damage.

It released roughly the energy of 1.4 t of TNT. Magnitude is logarithmic: each whole step means about 32 times more energy and 10 times larger waves on a seismogram. Depth matters too: at 54 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.

Compare M3.3 with M2.3

M3.3 releases about 34× the energy of M2.3, and its waves are about 10× taller on a seismogram. Energy: 1.4 t of TNT vs 43 kg of TNT.

Each square is the energy of one M2.3. Energy from log₁₀E = 1.5M + 4.8.

Aftershocks and nearby activity

9 later earthquakes within 30 km; the largest was M3.5 16 days ago. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M3.3

9 later earthquakes nearby. Aftershock rates typically fall off roughly as 1/time (Omori's law).

Did you feel it?

Reports from people help show where shaking was strong. They are anonymous and shown here in aggregate.

Reports close 14 days after an earthquake.

Reports on SeismoAtlas

No reports yet.

Event id pr71530363. First recorded here 28 Sept 2026, 17:32:14 UTC. Solutions: USGS · PR (usgs:pr71530363). Cite as: SeismoAtlas, “M3.3 earthquake 55 km N of Charlotte Amalie, Saint Thomas Island, U.S. Virgin Islands”, https://seismoatlas.com/earthquake/pr71530363-m3-3-earthquake-55-km-n-of-charlotte-amalie-saint-thomas-island-u-s-virgin, data from USGS.

JSON: /api/v1/events/pr71530363. SeismoAtlas is not an official warning service.

Time after mainshock (hours)	Magnitude	Depth (km)
187.14	3.0	77
202.43	3.0	20
264.60	2.9	76
299.17	3.5	79
323.45	3.5	16
491.16	3.0	20
515.64	2.9	13
520.47	3.4	85
699.78	2.9	24