143 km SSW of Adak, Alaska

Yes. A magnitude 4.4 earthquake was recorded 143 km SSW of Adak, Alaska at 05:21 UTC on 2024-12-09, 10 km deep.

2024-12-09 05:21 UTC · 10 km deep · released about 60 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: 2024-12-09 05:21 UTC
Magnitude: M 4.4 (mb)
Depth: 10 km below the surface
Felt: no reports yet
Measured shaking: intensity III (ShakeMap)
Status: Reviewed by a seismologist

USGS · last changed by USGS 634 days ago · we first saw it 634 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 129 km (80 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 60 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.4 would have released about 32 times as much.

Northridge, California 1994 M 6.7 2,800× the energy of this one
Mineral, Virginia 2011 M 5.8 130× the energy of this one
Magna, Utah 2020 M 5.7 89× the energy of this one
This earthquake M 4.4 about 60 tons of TNT
Around the size people start to feel M 3.0 this one released 130× 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 6.3 on 2024-12-09 — about 710 times the energy of this one.

Before 2016, the USGS record lists 21 earthquakes of M5 or more within 50 km; the five largest:

6.5 184 km SSW of Adak, Alaska · 41 km S of this epicentre Aug 15, 2007
6.4 146 km S of Adak, Alaska · 46 km ESE of this epicentre Mar 10, 1957
6.0 130 km SSW of Adak, Alaska · 15 km N of this epicentre Mar 20, 1927
6.0 161 km SSW of Adak, Alaska · 18 km SSW of this epicentre Jan 11, 1934
6.0 136 km S of Adak, Alaska · 35 km E of this epicentre Mar 11, 1957

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

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

2.4 110 km SSW of Adak, Alaska 16:25 UTC
3.3 122 km SSW of Adak, Alaska 16:25 UTC
2.7 134 km SSW of Adak, Alaska 15:12 UTC
2.1 111 km SSW of Adak, Alaska 15:00 UTC
2.2 124 km SSW of Adak, Alaska 14:54 UTC
2.2 111 km SSW of Adak, Alaska 14:47 UTC
2.1 101 km SSW of Adak, Alaska 14:24 UTC
2.8 133 km SSW of Adak, Alaska 14:09 UTC
2.2 125 km SSW of Adak, Alaska 13:58 UTC
3.9 118 km SSW of Adak, Alaska 13:09 UTC
2.2 119 km SSW of Adak, Alaska 13:07 UTC
2.1 104 km SSW of Adak, Alaska 12:59 UTC
2.7 111 km SSW of Adak, Alaska 12:19 UTC
2.6 124 km SSW of Adak, Alaska 11:53 UTC
2.5 128 km SSW of Adak, Alaska 11:50 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 22:09 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.