155 km ESE of Chignik, Alaska

Yes. A magnitude 2.2 earthquake was recorded 155 km ESE of Chignik, Alaska at 05:20 UTC on 2021-08-13, 1.9 km deep.

2021-08-13 05:20 UTC · 1.9 km deep · released about 60 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: 2021-08-13 05:20 UTC
Magnitude: M 2.2 (ml)
Depth: 1.9 km below the surface
Felt: no reports yet
Status: Reviewed by a seismologist

USGS · last changed by USGS 1907 days ago · we first saw it 1907 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 18 km (11 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 60 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.2 would have released about 32 times as much.

Mineral, Virginia 2011 M 5.8 250,000× the energy of this one
Magna, Utah 2020 M 5.7 180,000× the energy of this one
Around the size people start to feel M 3.0 16× the energy of this one
This earthquake M 2.2 about 60 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 4.5 on 2021-07-29 — about 2,800 times the energy of this one.

Before 2016, the USGS record lists 12 earthquakes of M5 or more within 50 km; the five largest:

7.0 113 km ESE of Chignik, Alaska · 42 km NW of this epicentre May 4, 1923
7.0 164 km SE of Chignik, Alaska · 36 km SSW of this epicentre Sep 4, 1989
6.9 143 km ESE of Chignik, Alaska · 20 km N of this epicentre Feb 13, 1951
6.9 171 km SW of Akhiok, Alaska · 26 km ENE of this epicentre Feb 6, 1964
6.6 128 km SE of Chignik, Alaska · 32 km W of this epicentre Jul 28, 1934

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

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

2.0 124 km ESE of Chignik, Alaska 10:16 UTC
2.9 186 km SSW of Akhiok, Alaska 22:38 UTC
2.7 167 km SE of Chignik, Alaska 03:18 UTC
2.8 155 km ESE of Chignik, Alaska 18:20 UTC
3.8 184 km SSW of Akhiok, Alaska 18:04 UTC
2.3 147 km SW of Akhiok, Alaska 22:41 UTC
2.4 south of Alaska 09:40 UTC
3.2 123 km ESE of Chignik, Alaska 03:20 UTC
2.1 149 km ESE of Chignik, Alaska 04:40 UTC
4.1 south of Alaska 22:20 UTC
2.4 137 km ESE of Chignik, Alaska 19:37 UTC
2.1 158 km ESE of Chignik, Alaska 05:30 UTC
2.4 148 km ESE of Chignik, Alaska 01:30 UTC
3.9 190 km SSW of Akhiok, Alaska 10:14 UTC
2.5 174 km SE of Chignik, Alaska 23:28 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 05:18 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.