57 km N of Chickaloon, 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 4 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 6.1 on 2021-05-31 — about 250,000 times the energy of this one.

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

1. 5.8 37 km ENE of Susitna North, Alaska · 35 km W of this epicentre Jul 3, 1929
2. 5.3 55 km NNE of Chickaloon, Alaska · 20 km ESE of this epicentre Jul 17, 1979
3. 5.1 25 km ENE of Susitna North, Alaska · 46 km W of this epicentre May 12, 1978
4. 5.0 70 km ENE of Chase, Alaska · 47 km NNW of this epicentre Feb 5, 1974
5. 5.0 59 km NW of Eureka Roadhouse, Alaska · 31 km E of this epicentre Feb 27, 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 62.3130, -148.5210. Map © OpenStreetMap contributors.

Nearby places

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

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

1. 2.5 64 km ENE of Susitna North, Alaska 19:08 UTC
2. 1.4 18 km N of Chickaloon, Alaska 08:44 UTC
3. 1.1 15 km N of Chickaloon, Alaska 07:26 UTC
4. 1.6 20 km NNW of Chickaloon, Alaska 05:06 UTC
5. 1.7 65 km N of Chickaloon, Alaska 18:25 UTC
6. 1.6 48 km NNE of Chickaloon, Alaska 05:22 UTC
7. 2.3 54 km ENE of Susitna North, Alaska 02:41 UTC
8. 2.1 35 km N of Sutton-Alpine, Alaska 06:32 UTC
9. 2.7 35 km N of Sutton-Alpine, Alaska 03:10 UTC
10. 1.4 39 km N of Sutton-Alpine, Alaska 07:16 UTC
11. 1.6 69 km NNE of Chickaloon, Alaska 18:42 UTC
12. 1.8 68 km NNW of Glacier View, Alaska 13:11 UTC
13. 2.1 54 km N of Chickaloon, Alaska 10:05 UTC
14. 2.8 78 km N of Chickaloon, Alaska 22:33 UTC
15. 2.4 20 km N of Sutton-Alpine, Alaska 19:06 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 21:51 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

Revisions

USGS refines a solution as more stations report. Every change we have seen is listed here.

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.