223 km SE of Chignik, Alaska

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

How big was it?

This earthquake released about 30 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.2 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 5,600× the energy of this one
2. Mineral, Virginia 2011 M 5.8 250× the energy of this one
3. Magna, Utah 2020 M 5.7 180× the energy of this one
4. This earthquake M 4.2 about 30 tons of TNT
5. Around the size people start to feel M 3.0 this one released 63× 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.

Where

Epicentre 54.7580, -156.1286. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.7 202 km SE of Chignik, Alaska 18:16 UTC
2. 3.5 205 km SE of Chignik, Alaska 10:01 UTC
3. 2.4 209 km SE of Chignik, Alaska 03:04 UTC
4. 2.4 217 km SE of Perryville, Alaska 05:16 UTC
5. 2.7 183 km SE of Chignik, Alaska 01:56 UTC
6. 2.8 229 km SE of Chignik, Alaska 03:50 UTC
7. 3.7 199 km SE of Chignik, Alaska 15:54 UTC
8. 2.8 213 km SE of Perryville, Alaska 13:57 UTC
9. 2.7 195 km SE of Chignik, Alaska 08:48 UTC
10. 3.7 207 km SE of Chignik, Alaska 12:17 UTC
11. 2.4 195 km SE of Chignik, Alaska 20:30 UTC
12. 2.7 193 km SE of Chignik, Alaska 21:43 UTC
13. 3.7 201 km SE of Chignik, Alaska 06:34 UTC
14. 3.4 194 km SE of Chignik, Alaska 10:23 UTC
15. 2.8 209 km SE of Chignik, Alaska 10:17 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 12:40 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

For this area

The largest earthquake within 50 km in our catalogue was M 5.6 on 2021-09-16 — it released about 130 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

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.