147 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 43 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.3 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 4,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 180× the energy of this one
3. Magna, Utah 2020 M 5.7 130× the energy of this one
4. This earthquake M 4.3 about 43 tons of TNT
5. Around the size people start to feel M 3.0 this one released 89× 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 55.2592, -156.9366. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.7 127 km SSE of Chignik, Alaska 13:03 UTC
2. 2.6 140 km SSE of Chignik, Alaska 13:01 UTC
3. 2.8 157 km SSE of Chignik, Alaska 12:56 UTC
4. 4.3 134 km SE of Chignik, Alaska 12:42 UTC
5. 2.7 143 km SE of Perryville, Alaska 12:36 UTC
6. 3.6 137 km SE of Chignik, Alaska 12:32 UTC
7. 3.5 126 km SE of Chignik, Alaska 12:23 UTC
8. 2.6 153 km SSE of Chignik, Alaska 12:04 UTC
9. 3.2 137 km SE of Chignik, Alaska 11:56 UTC
10. 3.0 149 km SSE of Chignik, Alaska 11:55 UTC
11. 3.5 131 km SE of Perryville, Alaska 11:47 UTC
12. 3.5 148 km SSE of Chignik, Alaska 11:41 UTC
13. 3.5 126 km SSE of Chignik, Alaska 11:29 UTC
14. 3.2 151 km SE of Chignik, Alaska 11:16 UTC
15. 4.2 131 km SSE of Chignik, Alaska 11:08 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 15:02 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 5.9 on 2021-07-29 — it released about 250 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.