133 km W of Adak, Alaska

Yes. A magnitude 2.7 earthquake was recorded 133 km W of Adak, Alaska at 20:47 UTC on 2021-09-12, 141 km deep.

2021-09-12 20:47 UTC · 141 km deep · released about 340 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: 2021-09-12 20:47 UTC
Magnitude: M 2.7 (ml)
Depth: 141 km below the surface
Felt: no reports yet
Status: Reviewed by a seismologist

USGS · last changed by USGS 1817 days ago · we first saw it 1817 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 340 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

Mineral, Virginia 2011 M 5.8 45,000× the energy of this one
Magna, Utah 2020 M 5.7 32,000× the energy of this one
Around the size people start to feel M 3.0 2.8× the energy of this one
This earthquake M 2.7 about 340 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.

For this area

The largest earthquake within 50 km since 2016 was M 6.2 on 2017-05-08 — about 180,000 times the energy of this one.

Before 2016, the USGS record lists 52 earthquakes of M5 or more within 50 km; the five largest:

6.6 174 km W of Adak, Alaska · 41 km W of this epicentre Apr 16, 2008
6.4 118 km WSW of Adak, Alaska · 41 km SSE of this epicentre Sep 26, 2012
6.3 155 km WSW of Adak, Alaska · 49 km SSW of this epicentre Jul 17, 1929
6.3 128 km W of Adak, Alaska · 8 km NE of this epicentre May 10, 1939
6.2 102 km WSW of Adak, Alaska · 48 km SE of this epicentre Aug 13, 1924

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

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

1.8 101 km W of Adak, Alaska 04:34 UTC
1.9 127 km WSW of Adak, Alaska 11:49 UTC
2.2 134 km W of Adak, Alaska 01:47 UTC
1.6 155 km WSW of Adak, Alaska 01:46 UTC
1.6 154 km W of Adak, Alaska 14:49 UTC
1.6 108 km WSW of Adak, Alaska 21:51 UTC
1.8 155 km W of Adak, Alaska 18:40 UTC
2.3 120 km W of Adak, Alaska 07:11 UTC
3.0 142 km WSW of Adak, Alaska 16:21 UTC
1.5 130 km WSW of Adak, Alaska 00:39 UTC
1.8 128 km WSW of Adak, Alaska 00:10 UTC
1.5 126 km W of Adak, Alaska 02:24 UTC
1.9 128 km WSW of Adak, Alaska 03:26 UTC
2.6 105 km W of Adak, Alaska 01:59 UTC
1.8 167 km W of Adak, Alaska 16:43 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 10:49 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.