146 km ENE of Atka, Alaska

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

At this magnitude and depth it was probably too small to be felt, even directly above it. 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 1,300 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 250,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 11,000× the energy of this one
3. Magna, Utah 2020 M 5.7 7,900× the energy of this one
4. This earthquake M 3.1 about 1,300 lb of TNT
5. Around the size people start to feel M 3.0 this one released 1.4× 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 2023-09-24 — about 710 times the energy of this one.

Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:

1. 6.5 173 km ENE of Atka, Alaska · 37 km NNE of this epicentre Dec 6, 1930
2. 5.4 156 km ENE of Atka, Alaska · 29 km SE of this epicentre May 12, 2013

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 52.6987, -172.2165. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 3.1 145 km ENE of Atka, Alaska 15:01 UTC
2. 2.9 171 km ENE of Atka, Alaska 05:54 UTC
3. 2.7 172 km E of Atka, Alaska 10:59 UTC
4. 2.9 177 km ENE of Atka, Alaska 03:47 UTC
5. 3.9 170 km E of Atka, Alaska 20:15 UTC
6. 4.4 171 km E of Atka, Alaska 20:10 UTC
7. 3.0 173 km E of Atka, Alaska 19:57 UTC
8. 4.4 167 km E of Atka, Alaska 12:46 UTC
9. 5.6 172 km ENE of Atka, Alaska 12:16 UTC
10. 3.2 174 km ENE of Atka, Alaska 23:27 UTC
11. 4.9 168 km E of Atka, Alaska 21:37 UTC
12. 3.7 127 km E of Atka, Alaska 16:45 UTC
13. 3.4 134 km E of Atka, Alaska 00:16 UTC
14. 3.6 118 km ENE of Atka, Alaska 03:34 UTC
15. 2.2 127 km ENE of Atka, Alaska 01:48 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 08:10 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.