165 km SE of Nikolski, Alaska

This was a moderate earthquake. Shaking at this size can damage poorly built structures close to the epicentre. 5 people have reported feeling it to USGS.

How big was it?

This earthquake released about 950 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 6.2 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 180× the energy of this one
2. Mineral, Virginia 2011 M 5.8 7.9× the energy of this one
3. Magna, Utah 2020 M 5.7 5.6× the energy of this one
4. This earthquake M 5.2 about 950 tons of TNT
5. Around the size people start to feel M 3.0 this one released 2,000× 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 51.9366, -167.0658. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.6 148 km SE of Nikolski, Alaska 17:45 UTC
2. 2.3 149 km SE of Nikolski, Alaska 10:33 UTC
3. 2.2 Fox Islands, Aleutian Islands, Alaska 05:20 UTC
4. 2.8 149 km ESE of Nikolski, Alaska 02:24 UTC
5. 2.3 125 km ESE of Nikolski, Alaska 21:25 UTC
6. 2.2 171 km SE of Nikolski, Alaska 16:29 UTC
7. 2.7 189 km SE of Nikolski, Alaska 15:21 UTC
8. 2.9 184 km SE of Nikolski, Alaska 08:53 UTC
9. 1.8 120 km SE of Nikolski, Alaska 16:51 UTC
10. 1.9 148 km SE of Nikolski, Alaska 11:01 UTC
11. 2.1 192 km SE of Nikolski, Alaska 04:03 UTC
12. 2.4 162 km ESE of Nikolski, Alaska 12:00 UTC
13. 2.7 143 km ESE of Nikolski, Alaska 01:55 UTC
14. 2.8 south of the Aleutian Islands 07:08 UTC
15. 2.1 168 km SE of Nikolski, Alaska 17:03 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 17:50 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 4.9 on 2017-12-10.

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.