103 km S of Atka, 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 51.2661, -174.1940. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.9 113 km SSE of Atka, Alaska 15:31 UTC
2. 2.7 134 km S of Atka, Alaska 10:40 UTC
3. 2.9 109 km S of Atka, Alaska 18:00 UTC
4. 2.8 79 km SSW of Atka, Alaska 08:42 UTC
5. 3.3 78 km SSW of Atka, Alaska 08:20 UTC
6. 2.9 74 km SSW of Atka, Alaska 02:03 UTC
7. 2.5 134 km SSE of Atka, Alaska 09:25 UTC
8. 3.2 Andreanof Islands, Aleutian Islands, Alaska 17:30 UTC
9. 3.3 100 km S of Atka, Alaska 16:06 UTC
10. 3.6 Andreanof Islands, Aleutian Islands, Alaska 11:36 UTC
11. 2.4 99 km S of Atka, Alaska 20:21 UTC
12. 2.4 Andreanof Islands, Aleutian Islands, Alaska 00:34 UTC
13. 2.4 126 km S of Atka, Alaska 08:23 UTC
14. 2.2 70 km S of Atka, Alaska 18:49 UTC
15. 2.7 108 km S of Atka, Alaska 21:44 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 21:15 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 6.3 on 2016-03-12 — it released about 1,000 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.