258 km SSE 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 since 2016 was M 5.0 on 2016-10-01 — about 1.4 times the energy of this one.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

1. 5.9 228 km S of False Pass, Alaska · 42 km NW of this epicentre Oct 13, 1972
2. 5.3 223 km S of False Pass, Alaska · 38 km NW of this epicentre Mar 12, 2015
3. 5.0 240 km SSE of False Pass, Alaska · 37 km NE of this epicentre Mar 15, 1982

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 52.5802, -162.5853. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 3.2 209 km S of False Pass, Alaska 03:22 UTC
2. 2.9 227 km S of False Pass, Alaska 01:20 UTC
3. 3.0 229 km S of False Pass, Alaska 13:06 UTC
4. 3.2 253 km SE of Akutan, Alaska 09:06 UTC
5. 3.1 249 km SE of Akutan, Alaska 08:00 UTC
6. 3.5 263 km S of False Pass, Alaska 22:12 UTC
7. 2.6 219 km SSE of False Pass, Alaska 15:49 UTC
8. 2.9 245 km S of False Pass, Alaska 03:38 UTC
9. 2.7 233 km SSE of False Pass, Alaska 10:44 UTC
10. 2.8 229 km SSE of False Pass, Alaska 05:14 UTC
11. 3.3 269 km S of False Pass, Alaska 20:08 UTC
12. 2.9 215 km S of False Pass, Alaska 10:45 UTC
13. 3.4 262 km SE of Akutan, Alaska 00:18 UTC
14. 3.2 245 km S of False Pass, Alaska 22:40 UTC
15. 3.3 244 km SE of Akutan, Alaska 17:15 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 02:59 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.