Andreanof Isl., Aleutian Islands, Alaska

Yes. A magnitude 4.0 earthquake was recorded in Andreanof Isl., Aleutian Islands, Alaska at 13:21 UTC on 2022-01-10, 10 km deep.

2022-01-10 13:21 UTC · 10 km deep · released about 15 tons of TNT

Felt it? Tell USGS Check my area

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: 2022-01-10 13:21 UTC
Magnitude: M 4.0 (mb)
Depth: 10 km below the surface
Felt: no reports yet
Status: Reviewed by a seismologist

USGS · last changed by USGS 1700 days ago · we first saw it 1700 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 96 km (60 mi) from the epicentre. Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

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.

For this area

The largest earthquake within 50 km since 2016 was M 5.4 on 2019-09-09 — about 130 times the energy of this one.

Before 2016, the USGS record lists 13 earthquakes of M5 or more within 50 km; the five largest:

6.5 184 km SSW of Adak, Alaska · 45 km WNW of this epicentre Aug 15, 2007
6.2 204 km S of Adak, Alaska · 18 km ESE of this epicentre Dec 9, 1918
6.1 198 km S of Adak, Alaska · 7 km ESE of this epicentre May 22, 1957
6.1 189 km S of Adak, Alaska · 8 km NNW of this epicentre Jul 3, 1960
6.0 194 km SSW of Adak, Alaska · 33 km WNW of this epicentre Nov 11, 1993

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

Map loads when it scrolls into view

Aftershocks so far

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

2.2 195 km SSW of Adak, Alaska 02:08 UTC
2.0 187 km SSW of Adak, Alaska 08:47 UTC
2.4 147 km S of Adak, Alaska 06:07 UTC
2.7 191 km S of Adak, Alaska 18:21 UTC
3.5 167 km SSW of Adak, Alaska 13:16 UTC
2.4 150 km S of Adak, Alaska 07:14 UTC
2.4 205 km S of Adak, Alaska 06:22 UTC
2.1 178 km S of Adak, Alaska 18:24 UTC
3.0 174 km S of Adak, Alaska 08:14 UTC
2.2 188 km S of Adak, Alaska 13:30 UTC
2.2 158 km S of Adak, Alaska 11:00 UTC
3.8 175 km S of Adak, Alaska 05:13 UTC
2.2 183 km SSW of Adak, Alaska 13:17 UTC
3.0 202 km S of Adak, Alaska 12:25 UTC
2.8 172 km SSW of Adak, Alaska 13:18 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 08:20 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.