167 km S of Adak, Alaska

Yes. A magnitude 2.7 earthquake was recorded 167 km S of Adak, Alaska at 22:27 UTC on 2020-07-21, 10 km deep.

2020-07-21 22:27 UTC · 10 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: 2020-07-21 22:27 UTC
Magnitude: M 2.7 (ml)
Depth: 10 km below the surface
Felt: no reports yet
Nearest mapped fault: Alaska-Aleutian subduction zone, 12 km from its surface trace — near is not the same as on
Status: Reviewed by a seismologist

USGS · last changed by USGS 2239 days ago · we first saw it 2239 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, people at rest would likely notice it out to about 23 km (14 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 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 4.7 on 2016-11-29 — about 1,000 times the energy of this one.

Before 2016, the USGS record lists 15 earthquakes of M5 or more within 50 km; the five largest:

6.4 146 km S of Adak, Alaska · 36 km NW of this epicentre Mar 10, 1957
6.2 204 km S of Adak, Alaska · 45 km SW of this epicentre Dec 9, 1918
6.1 198 km S of Adak, Alaska · 46 km SW of this epicentre May 22, 1957
6.1 189 km S of Adak, Alaska · 47 km WSW of this epicentre Jul 3, 1960
6.0 136 km S of Adak, Alaska · 49 km NW 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

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

2.6 162 km S of Adak, Alaska 01:56 UTC
2.6 134 km S of Adak, Alaska 09:48 UTC
2.4 189 km SSE of Adak, Alaska 09:21 UTC
2.2 184 km S of Adak, Alaska 04:58 UTC
3.6 212 km S of Adak, Alaska 05:03 UTC
2.2 199 km S of Adak, Alaska 15:09 UTC
3.1 Andreanof Islands, Aleutian Islands, Alaska 19:03 UTC
2.4 142 km S of Adak, Alaska 16:15 UTC
2.4 Andreanof Islands, Aleutian Islands, Alaska 14:51 UTC
2.2 187 km SSE of Adak, Alaska 07:16 UTC
2.6 Andreanof Islands, Aleutian Islands, Alaska 09:05 UTC
2.5 171 km S of Adak, Alaska 02:23 UTC
2.1 154 km S of Adak, Alaska 02:21 UTC
2.6 Andreanof Islands, Aleutian Islands, Alaska 07:37 UTC
1.6 123 km S of Adak, Alaska 01:43 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 03:54 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.