159 km S of False Pass, Alaska

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

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.

Where

Epicentre 53.4268, -163.6238. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 3.1 162 km S of False Pass, Alaska 14:39 UTC
2. 2.7 155 km S of False Pass, Alaska 14:18 UTC
3. 4.3 154 km ESE of Akutan, Alaska 22:31 UTC
4. 2.7 162 km S of False Pass, Alaska 01:08 UTC
5. 2.2 Unimak Island region, Alaska 19:41 UTC
6. 2.6 155 km S of False Pass, Alaska 11:25 UTC
7. 2.5 166 km S of False Pass, Alaska 11:17 UTC
8. 2.7 165 km S of False Pass, Alaska 09:56 UTC
9. 2.5 177 km S of False Pass, Alaska 22:23 UTC
10. 3.8 163 km S of False Pass, Alaska 20:06 UTC
11. 2.4 161 km S of False Pass, Alaska 20:00 UTC
12. 2.5 163 km S of False Pass, Alaska 18:52 UTC
13. 3.2 176 km S of False Pass, Alaska 16:51 UTC
14. 2.5 170 km S of False Pass, Alaska 16:05 UTC
15. 2.4 172 km S of False Pass, Alaska 15:16 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 12:54 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

For this area

The largest earthquake within 50 km in our catalogue was M 5.9 on 2016-10-27 — it released about 16,000 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

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.