172 km WSW of Adak, Alaska

Yes. A magnitude 3.1 earthquake was recorded 172 km WSW of Adak, Alaska at 02:31 UTC on 2019-03-08, 10 km deep.

2019-03-08 02:31 UTC · 10 km deep · released about 1,300 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: 2019-03-08 02:31 UTC
Magnitude: M 3.1 (ml)
Depth: 10 km below the surface
Felt: no reports yet
Status: Reviewed by a seismologist

USGS · last changed by USGS 2730 days ago · we first saw it 2730 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 41 km (25 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 1,300 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

Northridge, California 1994 M 6.7 250,000× the energy of this one
Mineral, Virginia 2011 M 5.8 11,000× the energy of this one
Magna, Utah 2020 M 5.7 7,900× the energy of this one
This earthquake M 3.1 about 1,300 lb of TNT
Around the size people start to feel M 3.0 this one released 1.4× 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 2017-09-11 — about 1,000 times the energy of this one.

Before 2016, the USGS record lists 243 earthquakes of M5 or more within 50 km; the five largest:

7.2 162 km WSW of Adak, Alaska · 20 km N of this epicentre Mar 16, 1957
7.2 207 km WSW of Adak, Alaska · 44 km WNW of this epicentre Dec 19, 2007
7.0 148 km WSW of Adak, Alaska · 24 km ENE of this epicentre Mar 11, 1957
6.9 203 km WSW of Adak, Alaska · 40 km WNW of this epicentre Mar 31, 1913
6.9 151 km WSW of Adak, Alaska · 22 km NE of this epicentre May 15, 1993

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

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

2.1 188 km WSW of Adak, Alaska 22:07 UTC
1.6 194 km WSW of Adak, Alaska 05:01 UTC
1.7 186 km WSW of Adak, Alaska 04:06 UTC
1.8 136 km WSW of Adak, Alaska 20:33 UTC
2.1 176 km WSW of Adak, Alaska 19:28 UTC
2.5 205 km WSW of Adak, Alaska 17:09 UTC
2.2 144 km WSW of Adak, Alaska 04:43 UTC
1.7 189 km WSW of Adak, Alaska 11:33 UTC
1.8 201 km WSW of Adak, Alaska 03:50 UTC
1.6 129 km WSW of Adak, Alaska 20:45 UTC
2.0 138 km WSW of Adak, Alaska 06:00 UTC
2.3 192 km W of Adak, Alaska 06:57 UTC
2.6 166 km WSW of Adak, AK 04:11 UTC
2.5 149 km WSW of Adak, Alaska 08:04 UTC
2.0 145 km WSW of Adak, Alaska 03:41 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 08:39 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.