143 km ESE of Akutan, Alaska

Yes. A magnitude 3.7 earthquake was recorded 143 km ESE of Akutan, Alaska at 05:21 UTC on 2017-05-30, 10 km deep.

2017-05-30 05:21 UTC · 10 km deep · released about 5.4 tons 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: 2017-05-30 05:21 UTC
Magnitude: M 3.7 (mb)
Depth: 10 km below the surface
Felt: no reports yet
Status: Reviewed by a seismologist

USGS · last changed by USGS 2741 days ago · we first saw it 2741 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 75 km (47 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 5.4 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.7 would have released about 32 times as much.

Northridge, California 1994 M 6.7 32,000× the energy of this one
Mineral, Virginia 2011 M 5.8 1,400× the energy of this one
Magna, Utah 2020 M 5.7 1,000× the energy of this one
This earthquake M 3.7 about 5.4 tons of TNT
Around the size people start to feel M 3.0 this one released 11× 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 5.1 on 2016-10-27 — about 130 times the energy of this one.

Before 2016, the USGS record lists 66 earthquakes of M5 or more within 50 km; the five largest:

6.6 146 km ESE of Akutan, Alaska · 4 km SE of this epicentre Apr 1, 1946
6.2 Unimak Island region, Alaska · 26 km NNW of this epicentre Oct 14, 1933
6.2 136 km SE of Akutan, Alaska · 21 km SW of this epicentre Apr 1, 1946
6.2 136 km S of False Pass, Alaska · 11 km NNE of this epicentre Apr 2, 1946
6.2 184 km SE of Akutan, Alaska · 47 km SSE of this epicentre Apr 6, 1946

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

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

2.2 102 km S of False Pass, Alaska 15:25 UTC
2.1 114 km SSW of False Pass, Alaska 06:20 UTC
2.6 141 km ESE of Akutan, Alaska 12:25 UTC
2.6 165 km S of False Pass, Alaska 12:53 UTC
2.3 159 km ESE of Akutan, Alaska 07:39 UTC
2.1 162 km ESE of Akutan, Alaska 23:19 UTC
2.4 169 km ESE of Akutan, Alaska 11:01 UTC
2.1 108 km ESE of Akutan, Alaska 20:40 UTC
2.3 106 km SSW of False Pass, Alaska 15:28 UTC
2.0 110 km SSW of False Pass, Alaska 19:52 UTC
2.5 103 km S of False Pass, Alaska 12:21 UTC
2.4 130 km ESE of Akutan, Alaska 10:08 UTC
2.1 99 km S of False Pass, Alaska 00:12 UTC
3.0 115 km ESE of Akutan, Alaska 07:24 UTC
2.5 119 km S of False Pass, Alaska 04:47 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 09:54 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.