88 km WSW of Akhiok, Alaska

2022-03-20 16:35 UTC · 8.3 km deep · released about 43 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: 2022-03-20 16:35 UTC
Magnitude: M 4.3 (mb)
Depth: 8.3 km below the surface
Felt: no reports yet
Measured shaking: intensity III (ShakeMap)
Nearest: Kodiak Island Borough, 144 km NE
Status: Reviewed by a seismologist

USGS · last changed by USGS 1583 days ago · we first saw it 1583 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 43 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.3 would have released about 32 times as much.

Northridge, California 1994 M 6.7 4,000× the energy of this one
Mineral, Virginia 2011 M 5.8 180× the energy of this one
Magna, Utah 2020 M 5.7 130× the energy of this one
This earthquake M 4.3 about 43 tons of TNT
Around the size people start to feel M 3.0 this one released 89× 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 56.7891, -155.6008. Map © OpenStreetMap contributors.

Nearby places

Place	Distance	Direction
Kodiak Island Borough, AK	144 km (89 mi)	SW of here	earthquakes near Kodiak Island Borough

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

Aftershocks so far

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

2.3 57 km W of Akhiok, Alaska 21:39 UTC
1.9 105 km WSW of Akhiok, Alaska 20:08 UTC
2.8 91 km SW of Akhiok, Alaska 03:55 UTC
2.2 97 km SE of Ugashik, Alaska 17:07 UTC
1.7 77 km SW of Karluk, Alaska 17:23 UTC
1.7 97 km W of Akhiok, Alaska 07:26 UTC
1.8 77 km WSW of Akhiok, Alaska 09:03 UTC
2.7 96 km W of Akhiok, Alaska 18:08 UTC
2.0 94 km ESE of Ugashik, Alaska 20:34 UTC
1.5 94 km SE of Ugashik, Alaska 17:48 UTC
2.2 115 km WSW of Akhiok, Alaska 03:47 UTC
1.6 97 km W of Akhiok, Alaska 04:46 UTC
1.8 118 km SE of Ugashik, Alaska 10:59 UTC
2.4 59 km WSW of Akhiok, Alaska 07:06 UTC
1.6 Alaska Peninsula 19:37 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 12:41 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 4.3 on 2018-07-01.

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.