south of Alaska

2023-08-03 16:01 UTC · 15 km deep · released about 950 lb 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: 2023-08-03 16:01 UTC
Magnitude: M 3.0 (ml)
Depth: 15 km below the surface
Felt: no reports yet
Status: Reviewed by a seismologist

USGS · last changed by USGS 983 days ago · we first saw it 983 days ago

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 950 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.

Northridge, California 1994 M 6.7 350,000× the energy of this one
Mineral, Virginia 2011 M 5.8 16,000× the energy of this one
Magna, Utah 2020 M 5.7 11,000× the energy of this one
This earthquake M 3.0 about 950 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.

Where

Map loads when it scrolls into view

Epicentre 53.8782, -155.5757. Map © OpenStreetMap contributors.

Aftershocks so far

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

3.4 south of Alaska 16:37 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 23:22 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.