Andreanof Islands, Aleutian Islands, Alaska

Yes. A magnitude 2.8 earthquake was recorded in the Andreanof Islands, Aleutian Islands, Alaska at 16:40 UTC on 2020-10-31, 26 km deep.

2020-10-31 16:40 UTC · 26 km deep · released about 480 lb 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: 2020-10-31 16:40 UTC
Magnitude: M 2.8 (ml)
Depth: 26 km below the surface
Felt: no reports yet
Status: Reviewed by a seismologist

USGS · last changed by USGS 2125 days ago · we first saw it 2125 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 8 km (5 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 480 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

Mineral, Virginia 2011 M 5.8 32,000× the energy of this one
Magna, Utah 2020 M 5.7 22,000× the energy of this one
Around the size people start to feel M 3.0 2× the energy of this one
This earthquake M 2.8 about 480 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 5.6 on 2016-03-12 — about 16,000 times the energy of this one.

Before 2016, the USGS record lists 29 earthquakes of M5 or more within 50 km; the five largest:

6.6 89 km S of Atka, Alaska · 43 km NNW of this epicentre Mar 10, 1957
6.1 87 km S of Atka, Alaska · 41 km N of this epicentre Jun 9, 1983
5.9 81 km S of Atka, Alaska · 48 km NNW of this epicentre May 9, 1986
5.8 131 km S of Atka, Alaska · 24 km W of this epicentre Apr 24, 1928
5.8 83 km S of Atka, Alaska · 45 km N of this epicentre May 9, 1986

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

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

3.9 83 km SSE of Atka, Alaska 08:41 UTC
4.0 97 km S of Atka, Alaska 18:14 UTC
2.7 108 km S of Atka, Alaska 14:56 UTC
2.9 95 km S of Atka, Alaska 15:13 UTC
2.1 91 km S of Atka, Alaska 17:27 UTC
2.7 96 km SSE of Atka, Alaska 10:23 UTC
2.6 87 km S of Atka, Alaska 10:22 UTC
1.7 109 km S of Atka, Alaska 12:09 UTC
2.8 93 km SSE of Atka, Alaska 02:09 UTC
2.1 178 km S of Atka, Alaska 15:16 UTC
2.1 165 km SSE of Atka, Alaska 00:24 UTC
1.6 90 km SSE of Atka, Alaska 00:23 UTC
2.5 102 km SSE of Atka, Alaska 10:54 UTC
2.2 103 km S of Atka, Alaska 05:28 UTC
2.2 173 km SSE of Atka, Alaska 18:13 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 07:21 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.