116 km E of Chignik, Alaska

Yes. A magnitude 3.1 earthquake was recorded 116 km E of Chignik, Alaska at 07:48 UTC on 2023-02-21, 27 km deep.

2023-02-21 07:48 UTC · 27 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: 2023-02-21 07:48 UTC
Magnitude: M 3.1 (ml)
Depth: 27 km below the surface
Felt: no reports yet
Status: Reviewed by a seismologist

USGS · last changed by USGS 1293 days ago · we first saw it 1293 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 32 km (20 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 6.9 on 2021-10-11 — about 500,000 times the energy of this one.

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

6.8 117 km SSE of Ugashik, Alaska · 34 km N of this epicentre May 29, 2015
6.4 77 km ESE of Chignik, Alaska · 45 km WSW of this epicentre Mar 24, 1972
6.4 104 km SSE of Ugashik, Alaska · 41 km NNW of this epicentre May 20, 1979
6.3 112 km E of Chignik, Alaska · 13 km SSW of this epicentre Feb 25, 1953
6.1 132 km E of Chignik, Alaska · 19 km ESE of this epicentre Sep 13, 1911

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

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

1.9 98 km E of Chignik, Alaska 02:55 UTC
2.1 120 km E of Chignik, Alaska 02:55 UTC
2.6 122 km ESE of Chignik, Alaska 15:19 UTC
2.6 116 km E of Chignik, Alaska 19:07 UTC
2.5 115 km E of Chignik, Alaska 09:35 UTC
2.1 110 km E of Chignik, Alaska 00:13 UTC
2.2 111 km E of Chignik, Alaska 13:33 UTC
2.0 93 km ENE of Chignik, Alaska 10:24 UTC
2.1 96 km SSE of Ugashik, Alaska 14:30 UTC
2.3 96 km ENE of Chignik, Alaska 10:54 UTC
1.6 113 km SE of Ugashik, Alaska 19:50 UTC
1.7 100 km SSE of Ugashik, Alaska 22:51 UTC
2.7 121 km SE of Ugashik, Alaska 01:08 UTC
2.3 114 km E of Chignik, Alaska 09:12 UTC
3.0 121 km E of Chignik, Alaska 00:40 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 23:30 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.