100 km SSE of Akutan, Alaska

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 3 km (2 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 170 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 89,000× the energy of this one
2. Magna, Utah 2020 M 5.7 63,000× the energy of this one
3. Around the size people start to feel M 3.0 5.6× the energy of this one
4. This earthquake M 2.5 about 170 lb of TNT

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 5.3 on 2022-08-01 — about 16,000 times the energy of this one.

Before 2016, the USGS record lists 21 earthquakes of M5 or more within 50 km; the five largest:

1. 6.6 92 km SE of Akutan, Alaska · 43 km NE of this epicentre Feb 19, 2003
2. 6.5 83 km SE of Akutan, Alaska · 47 km NNE of this epicentre Oct 30, 1946
3. 6.1 90 km SE of Unalaska, Alaska · 47 km WSW of this epicentre Jan 25, 1982
4. 6.0 57 km SSE of Akutan, Alaska · 43 km NNW of this epicentre Jun 28, 1933
5. 5.9 66 km SSE of Akutan, Alaska · 36 km NW of this epicentre Sep 23, 1984

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 53.3416, -165.0438. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.1 125 km SSE of Akutan, Alaska 05:58 UTC
2. 2.2 77 km SE of Akutan, Alaska 11:55 UTC
3. 2.2 91 km SE of Akutan, Alaska 16:23 UTC
4. 2.1 75 km SE of Akutan, Alaska 07:09 UTC
5. 2.4 94 km SE of Akutan, Alaska 07:56 UTC
6. 2.1 53 km SSE of Akutan, Alaska 11:46 UTC
7. 2.2 68 km SSE of Akutan, Alaska 05:13 UTC
8. 2.1 75 km SSE of Akutan, Alaska 11:17 UTC
9. 2.7 94 km SSE of Akutan, Alaska 10:48 UTC
10. 1.8 71 km SSE of Akutan, Alaska 07:40 UTC
11. 2.0 83 km SSE of Akutan, Alaska 16:19 UTC
12. 2.3 91 km SE of Akutan, Alaska 19:24 UTC
13. 1.9 60 km SSE of Akutan, Alaska 14:28 UTC
14. 1.9 58 km SSE of Akutan, Alaska 14:03 UTC
15. 3.2 59 km SSE of Akutan, Alaska 06:23 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 04:46 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.