216 km SE of Akutan, 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 129 km (80 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 60 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.4 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 2,800× the energy of this one
2. Mineral, Virginia 2011 M 5.8 130× the energy of this one
3. Magna, Utah 2020 M 5.7 89× the energy of this one
4. This earthquake M 4.4 about 60 tons of TNT
5. Around the size people start to feel M 3.0 this one released 130× 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 2 earthquakes of M5 or more within 50 km:

1. 5.5 218 km SE of Akutan, Alaska · 7 km ENE of this epicentre May 3, 2010
2. 5.1 200 km SE of Akutan, Alaska · 19 km WNW of this epicentre Jul 8, 1989

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 52.5978, -163.7921. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 3.0 231 km SE of Akutan, Alaska 14:49 UTC
2. 3.0 212 km SE of Akutan, Alaska 21:53 UTC
3. 2.8 218 km SE of Akutan, Alaska 08:50 UTC
4. 2.4 192 km SE of Akutan, Alaska 22:14 UTC
5. 3.8 183 km SE of Akutan, Alaska 01:02 UTC
6. 2.5 198 km SE of Akutan, Alaska 12:59 UTC
7. 2.4 239 km SE of Akutan, Alaska 01:15 UTC
8. 2.9 202 km SE of Akutan, Alaska 04:46 UTC
9. 3.0 230 km SE of Akutan, Alaska 01:23 UTC
10. 3.0 215 km SE of Akutan, Alaska 13:05 UTC
11. 2.8 211 km SE of Akutan, Alaska 09:36 UTC
12. 2.3 204 km SE of Akutan, Alaska 03:46 UTC
13. 2.8 231 km SE of Akutan, Alaska 07:20 UTC
14. 3.4 197 km SE of Akutan, Alaska 05:56 UTC
15. 2.5 175 km SE of Akutan, Alaska 10:33 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 01:54 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.