143 km W of Adak, Alaska

Yes. A magnitude 3.1 earthquake was recorded 143 km W of Adak, Alaska at 20:06 UTC on 2016-10-22, 124 km deep.

2016-10-22 20:06 UTC · 124 km deep · released about 1,300 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: 2016-10-22 20:06 UTC
Magnitude: M 3.1 (ml)
Depth: 124 km below the surface
Felt: no reports yet
Status: Reviewed by a seismologist

USGS · last changed by USGS 1199 days ago · we first saw it 1199 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. 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 1,300 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

Northridge, California 1994 M 6.7 250,000× the energy of this one
Mineral, Virginia 2011 M 5.8 11,000× the energy of this one
Magna, Utah 2020 M 5.7 7,900× the energy of this one
This earthquake M 3.1 about 1,300 lb of TNT
Around the size people start to feel M 3.0 this one released 1.4× 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 5.3 on 2016-07-03 — about 2,000 times the energy of this one.

Before 2016, the USGS record lists 35 earthquakes of M5 or more within 50 km; the five largest:

6.6 174 km W of Adak, Alaska · 31 km W of this epicentre Apr 16, 2008
6.5 167 km WSW of Adak, Alaska · 49 km SSW of this epicentre Jan 27, 1943
6.4 187 km W of Adak, Alaska · 44 km W of this epicentre Apr 15, 2008
6.4 118 km WSW of Adak, Alaska · 47 km SE of this epicentre Sep 26, 2012
6.3 155 km WSW of Adak, Alaska · 48 km S of this epicentre Jul 17, 1929

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

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

1.6 140 km WSW of Adak, Alaska 14:05 UTC
2.0 131 km WSW of Adak, Alaska 16:47 UTC
2.2 118 km W of Adak, Alaska 00:01 UTC
1.6 126 km W of Adak, Alaska 02:57 UTC
1.8 125 km WSW of Adak, Alaska 07:38 UTC
1.9 140 km WSW of Adak, Alaska 14:40 UTC
1.9 166 km W of Adak, Alaska 12:26 UTC
1.9 164 km W of Adak, Alaska 04:28 UTC
3.6 133 km W of Adak, Alaska 21:28 UTC
2.6 175 km W of Adak, Alaska 08:23 UTC
2.2 178 km W of Adak, Alaska 07:58 UTC
1.6 108 km W of Adak, Alaska 05:06 UTC
2.1 168 km W of Adak, Alaska 16:53 UTC
1.9 178 km W of Adak, Alaska 11:21 UTC
2.0 170 km W of Adak, Alaska 07:50 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 20:02 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.