75 km WSW 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.

At this magnitude and depth, people at rest would likely notice it out to about 181 km (112 mi) from the epicentre. Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

How big was it?

This earthquake released about 340 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.9 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 500× the energy of this one
2. Mineral, Virginia 2011 M 5.8 22× the energy of this one
3. Magna, Utah 2020 M 5.7 16× the energy of this one
4. This earthquake M 4.9 about 340 tons of TNT
5. Around the size people start to feel M 3.0 this one released 710× 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.

For this area

The largest earthquake within 50 km (31 mi) since our catalogue begins in 2016. No other earthquake of M4 or more has been recorded this close in that time.

Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:

1. 6.4 60 km NE of Akutan, Alaska · 41 km SW of this epicentre Jul 27, 1944
2. 5.2 83 km SW of False Pass, Alaska · 49 km SSE of this epicentre Nov 19, 1993
3. 5.2 79 km SW of False Pass, Alaska · 49 km SSE of this epicentre Nov 20, 1993
4. 5.1 52 km W of False Pass, Alaska · 27 km NE of this epicentre Mar 4, 1999
5. 5.0 29 km W of False Pass, Alaska · 47 km ENE of this epicentre Apr 13, 1985

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 54.6939, -164.5535. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 3.8 102 km WNW of False Pass, Alaska 11:08 UTC
2. 1.5 49 km WSW of False Pass, Alaska 09:38 UTC
3. 4.7 90 km W of False Pass, Alaska 16:29 UTC
4. 1.7 45 km WNW of False Pass, Alaska 12:31 UTC
5. 2.2 75 km ENE of Akutan, Alaska 14:32 UTC
6. 2.2 68 km WSW of False Pass, Alaska 15:04 UTC
7. 3.6 69 km SW of False Pass, Alaska 14:36 UTC
8. 2.1 41 km W of False Pass, Alaska 12:00 UTC
9. 2.2 86 km ENE of Akutan, Alaska 12:12 UTC
10. 2.2 81 km SW of False Pass, Alaska 23:22 UTC
11. 2.4 69 km WSW of False Pass, Alaska 20:52 UTC
12. 2.0 63 km ENE of Akutan, Alaska 21:10 UTC
13. 2.8 88 km E of Akutan, Alaska 23:24 UTC
14. 2.8 71 km WSW of False Pass, Alaska 02:07 UTC
15. 2.8 70 km W of False Pass, Alaska 06:28 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 05:07 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

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.