127 km SE of Perryville, Alaska

Yes. A magnitude 2.3 earthquake was recorded 127 km SE of Perryville, Alaska at 11:15 UTC on 2021-10-06, less than 1 km deep.

2021-10-06 11:15 UTC · 0.4 km deep · released about 85 lb 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: 2021-10-06 11:15 UTC
Magnitude: M 2.3 (ml)
Depth: 0.4 km below the surface
Felt: no reports yet
Status: Reviewed by a seismologist

USGS · last changed by USGS 1803 days ago · we first saw it 1803 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 20 km (12 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 85 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

Mineral, Virginia 2011 M 5.8 180,000× the energy of this one
Magna, Utah 2020 M 5.7 130,000× the energy of this one
Around the size people start to feel M 3.0 11× the energy of this one
This earthquake M 2.3 about 85 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 8.2 on 2021-07-29 — about 710,000,000 times the energy of this one.

Before 2016, the USGS record lists 16 earthquakes of M5 or more within 50 km; the five largest:

8.2 1938 Semidi Islands, Alaska Earthquake · 46 km WSW of this epicentre Nov 10, 1938
6.9 105 km ESE of Perryville, Alaska · 22 km NW of this epicentre Nov 17, 1938
6.7 121 km SE of Chignik, Alaska · 29 km NE of this epicentre Feb 13, 1979
6.2 143 km SE of Perryville, Alaska · 45 km SSW of this epicentre Mar 25, 1927
6.0 98 km ESE of Perryville, Alaska · 29 km NW of this epicentre Jan 2, 1985

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

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Aftershocks so far

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

3.2 153 km SE of Perryville, Alaska 08:14 UTC
2.3 133 km SSE of Chignik, Alaska 00:39 UTC
2.5 119 km SE of Chignik, Alaska 23:21 UTC
2.0 147 km SE of Perryville, Alaska 20:14 UTC
2.3 122 km SE of Perryville, Alaska 21:04 UTC
4.9 133 km SE of Chignik, Alaska 21:41 UTC
3.0 135 km SE of Perryville, Alaska 02:42 UTC
2.4 158 km SSE of Chignik, Alaska 16:41 UTC
2.2 95 km ESE of Perryville, Alaska 06:43 UTC
4.5 147 km SE of Perryville, Alaska 18:08 UTC
2.7 142 km SE of Perryville, Alaska 18:06 UTC
3.2 142 km SE of Perryville, Alaska 17:54 UTC
2.3 156 km SSE of Chignik, Alaska 21:38 UTC
2.4 102 km SE of Chignik, Alaska 12:09 UTC
3.3 137 km SE of Perryville, Alaska 21:00 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 16:14 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.