Unimak Island region, 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 15 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.0 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 11,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 500× the energy of this one
3. Magna, Utah 2020 M 5.7 350× the energy of this one
4. This earthquake M 4.0 about 15 tons of TNT
5. Around the size people start to feel M 3.0 this one released 32× 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 53.5037, -163.8473. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 4.7 137 km SE of Akutan, Alaska 10:22 UTC
2. 2.3 Unimak Island region, Alaska 02:29 UTC
3. 1.9 105 km ESE of Akutan, Alaska 00:12 UTC
4. 2.0 108 km SSW of False Pass, Alaska 23:02 UTC
5. 1.9 104 km S of False Pass, Alaska 04:38 UTC
6. 2.6 118 km SSW of False Pass, Alaska 13:47 UTC
7. 2.7 155 km S of False Pass, Alaska 19:43 UTC
8. 2.6 144 km SE of Akutan, Alaska 16:29 UTC
9. 2.4 147 km ESE of Akutan, Alaska 12:30 UTC
10. 2.8 140 km S of False Pass, Alaska 17:42 UTC
11. 2.8 115 km SSW of False Pass, Alaska 22:54 UTC
12. 2.2 Unimak Island region, Alaska 05:09 UTC
13. 2.7 110 km SSW of False Pass, Alaska 21:48 UTC
14. 2.6 120 km SSW of False Pass, Alaska 21:44 UTC
15. 2.3 109 km S of False Pass, Alaska 16:25 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 18:42 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 5.7 on 2020-08-13 — it released about 350 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.