144 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 7.6 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.8 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 22,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 1,000× the energy of this one
3. Magna, Utah 2020 M 5.7 710× the energy of this one
4. This earthquake M 3.8 about 7.6 tons of TNT
5. Around the size people start to feel M 3.0 this one released 16× 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 53.5627, -163.1490. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.5 154 km S of False Pass, Alaska 08:20 UTC
2. 2.2 144 km SSE of False Pass, Alaska 21:04 UTC
3. 2.8 154 km SSE of False Pass, Alaska 17:43 UTC
4. 2.6 134 km SSE of False Pass, Alaska 12:58 UTC
5. 2.0 97 km S of False Pass, Alaska 08:26 UTC
6. 2.7 155 km S of False Pass, Alaska 19:43 UTC
7. 2.2 Unimak Island region, Alaska 05:09 UTC
8. 2.2 101 km S of False Pass, Alaska 09:58 UTC
9. 2.5 125 km SSE of False Pass, Alaska 09:24 UTC
10. 3.2 Unimak Island region, Alaska 19:32 UTC
11. 2.5 121 km S of False Pass, Alaska 18:07 UTC
12. 2.5 153 km S of False Pass, Alaska 08:05 UTC
13. 2.4 147 km SSE of False Pass, Alaska 10:39 UTC
14. 2.5 Unimak Island region, Alaska 03:09 UTC
15. 3.8 151 km S of False Pass, Alaska 00:06 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 20:52 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 1,400 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.