200 km SE of Chignik, Alaska

Yes. A magnitude 5.1 earthquake was recorded 200 km SE of Chignik, Alaska at 23:05 UTC on 2021-09-16, 33 km deep. 1 person has reported feeling it to USGS.

2021-09-16 23:05 UTC · 33 km deep · released about 670 tons of TNT

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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: 2021-09-16 23:05 UTC
Magnitude: M 5.1 (mww)
Depth: 33 km below the surface
Felt: 1 report · strongest reported intensity II
Measured shaking: intensity III (ShakeMap)
USGS impact alert: green
Tsunami: USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Status: Reviewed by a seismologist

USGS · last changed by USGS 326 days ago · we first saw it 326 days ago

This was a moderate earthquake. Shaking at this size can damage poorly built structures close to the epicentre.

At this magnitude and depth, people at rest would likely notice it out to about 203 km (126 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 670 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 6.1 would have released about 32 times as much.

Northridge, California 1994 M 6.7 250× the energy of this one
Mineral, Virginia 2011 M 5.8 11× the energy of this one
Magna, Utah 2020 M 5.7 7.9× the energy of this one
This earthquake M 5.1 about 670 tons of TNT
Around the size people start to feel M 3.0 this one released 1,400× 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 5.6 on 2021-09-16 — about 5.6 times the energy of this one.

Before 2016, the USGS record lists 10 earthquakes of M5 or more within 50 km; the five largest:

7.0 164 km SE of Chignik, Alaska · 43 km N of this epicentre Sep 4, 1989
6.2 189 km SE of Chignik, Alaska · 15 km W of this epicentre Mar 18, 1945
6.1 210 km SE of Chignik, Alaska · 46 km NE of this epicentre Nov 15, 1955
6.0 168 km SE of Chignik, Alaska · 36 km NNW of this epicentre Nov 16, 1938
5.6 171 km SE of Chignik, Alaska · 29 km NW of this epicentre Jun 22, 1970

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

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

2.8 231 km SE of Chignik, Alaska 22:35 UTC
2.5 220 km SE of Chignik, Alaska 07:32 UTC
2.6 244 km SE of Chignik, Alaska 14:11 UTC
2.7 206 km SE of Chignik, Alaska 11:48 UTC
3.0 239 km SE of Chignik, Alaska 10:19 UTC
2.3 216 km SE of Perryville, Alaska 03:33 UTC
2.8 201 km SE of Perryville, Alaska 14:37 UTC
4.4 209 km SE of Perryville, Alaska 11:25 UTC
2.5 170 km SE of Chignik, Alaska 00:12 UTC
2.8 208 km SE of Perryville, Alaska 18:13 UTC
2.5 204 km SE of Perryville, Alaska 23:07 UTC
2.5 212 km SE of Chignik, Alaska 12:44 UTC
4.2 223 km SE of Chignik, Alaska 18:17 UTC
2.6 187 km SE of Chignik, Alaska 14:15 UTC
3.0 190 km SE of Chignik, Alaska 00:57 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 19:13 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.