117 km SSW of False Pass, Alaska

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 1 person has reported feeling it to USGS.

How big was it?

This earthquake released about 85 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.5 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 2,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 89× the energy of this one
3. Magna, Utah 2020 M 5.7 63× the energy of this one
4. This earthquake M 4.5 about 85 tons of TNT
5. Around the size people start to feel M 3.0 this one released 180× 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 53.8541, -163.9832. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.2 107 km SSW of False Pass, Alaska 23:20 UTC
2. 2.4 94 km ESE of Akutan, Alaska 00:37 UTC
3. 1.9 114 km SSW of False Pass, Alaska 12:40 UTC
4. 2.4 114 km SSW of False Pass, Alaska 12:13 UTC
5. 2.2 83 km SW of False Pass, Alaska 02:29 UTC
6. 2.5 109 km S of False Pass, Alaska 12:40 UTC
7. 2.2 117 km SSW of False Pass, Alaska 10:49 UTC
8. 2.7 107 km ESE of Akutan, Alaska 05:15 UTC
9. 2.6 104 km SSW of False Pass, Alaska 02:00 UTC
10. 2.8 153 km S of False Pass, Alaska 00:15 UTC
11. 3.5 Unimak Island region, Alaska 13:28 UTC
12. 2.4 140 km ESE of Akutan, Alaska 15:37 UTC
13. 2.3 125 km ESE of Akutan, Alaska 03:45 UTC
14. 2.3 121 km ESE of Akutan, Alaska 21:13 UTC
15. 2.1 112 km SSW of False Pass, Alaska 02:25 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 16:15 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 5.0 on 2016-06-18 — it released about 5.6 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.