Fox Islands, Aleutian Islands, Alaska

Yes. A magnitude 3.6 earthquake was recorded in the Fox Islands, Aleutian Islands, Alaska at 14:31 UTC on 2017-10-06, 27 km deep.

2017-10-06 14:31 UTC · 27 km deep · released about 3.8 tons 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: 2017-10-06 14:31 UTC
Magnitude: M 3.6 (ml)
Depth: 27 km below the surface
Felt: no reports yet
Status: Reviewed by a seismologist

USGS · last changed by USGS 1192 days ago · we first saw it 1192 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 64 km (40 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 3.8 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.6 would have released about 32 times as much.

Northridge, California 1994 M 6.7 45,000× the energy of this one
Mineral, Virginia 2011 M 5.8 2,000× the energy of this one
Magna, Utah 2020 M 5.7 1,400× the energy of this one
This earthquake M 3.6 about 3.8 tons of TNT
Around the size people start to feel M 3.0 this one released 7.9× 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 4.9 on 2017-09-29 — about 89 times the energy of this one.

Before 2016, the USGS record lists 92 earthquakes of M5 or more within 50 km; the five largest:

6.6 135 km SW of Nikolski, Alaska · 22 km NW of this epicentre Dec 23, 1906
6.2 91 km SW of Nikolski, Alaska · 46 km NNE of this epicentre Feb 10, 1953
6.2 87 km SW of Nikolski, Alaska · 50 km NNE of this epicentre Oct 23, 1957
6.0 119 km SSW of Nikolski, Alaska · 16 km NNE of this epicentre Mar 29, 1931
6.0 128 km SW of Nikolski, Alaska · 39 km NW of this epicentre Jun 1, 1945

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

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

3.3 118 km SW of Nikolski, Alaska 21:20 UTC
3.6 108 km SSW of Nikolski, Alaska 01:50 UTC
2.7 106 km SSW of Nikolski, Alaska 01:34 UTC
3.0 110 km SSW of Nikolski, Alaska 10:54 UTC
2.3 93 km SSW of Nikolski, Alaska 12:06 UTC
3.0 129 km SW of Nikolski, Alaska 14:55 UTC
3.1 104 km SSW of Nikolski, Alaska 05:39 UTC
3.0 105 km SSW of Nikolski, Alaska 05:16 UTC
3.3 98 km SSW of Nikolski, Alaska 22:54 UTC
2.5 111 km SSW of Nikolski, Alaska 02:25 UTC
2.8 97 km SSW of Nikolski, Alaska 03:07 UTC
2.2 127 km SW of Nikolski, Alaska 11:57 UTC
3.2 164 km SW of Nikolski, Alaska 00:02 UTC
4.0 115 km SSW of Nikolski, Alaska 03:05 UTC
3.9 113 km SSW of Nikolski, Alaska 03:03 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 12:22 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.