190 km SW of Nikolski, 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 240 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.8 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 710× the energy of this one
2. Mineral, Virginia 2011 M 5.8 32× the energy of this one
3. Magna, Utah 2020 M 5.7 22× the energy of this one
4. This earthquake M 4.8 about 240 tons of TNT
5. Around the size people start to feel M 3.0 this one released 500× 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 51.9458, -171.1386. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 3.5 166 km WSW of Nikolski, Alaska 01:48 UTC
2. 2.7 Fox Islands, Aleutian Islands, Alaska 11:01 UTC
3. 3.5 178 km E of Atka, Alaska 04:49 UTC
4. 3.2 193 km SW of Nikolski, Alaska 12:22 UTC
5. 3.5 160 km SW of Nikolski, Alaska 23:35 UTC
6. 2.7 172 km SW of Nikolski, Alaska 00:30 UTC
7. 2.8 162 km SW of Nikolski, Alaska 11:46 UTC
8. 3.4 185 km E of Atka, Alaska 16:58 UTC
9. 3.5 159 km WSW of Nikolski, Alaska 17:22 UTC
10. 3.2 169 km WSW of Nikolski, Alaska 00:38 UTC
11. 2.8 182 km WSW of Nikolski, Alaska 15:34 UTC
12. 4.6 185 km WSW of Nikolski, Alaska 21:21 UTC
13. 3.4 182 km E of Atka, Alaska 08:35 UTC
14. 4.4 Fox Islands, Aleutian Islands, Alaska 14:04 UTC
15. 2.5 172 km SW of Nikolski, Alaska 21:44 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 16:04 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 2018-08-25 — it released about 45 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.