158 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 1.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 130,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 5,600× the energy of this one
3. Magna, Utah 2020 M 5.7 4,000× the energy of this one
4. This earthquake M 3.3 about 1.3 tons of TNT
5. Around the size people start to feel M 3.0 this one released 2.8× 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 53.4336, -163.2247. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 3.4 145 km S of False Pass, Alaska 12:55 UTC
2. 2.8 140 km S of False Pass, Alaska 16:36 UTC
3. 3.4 118 km S of False Pass, Alaska 16:01 UTC
4. 3.0 132 km S of False Pass, Alaska 10:23 UTC
5. 3.2 121 km S of False Pass, Alaska 00:37 UTC
6. 2.5 164 km S of False Pass, Alaska 00:34 UTC
7. 2.5 136 km S of False Pass, Alaska 08:04 UTC
8. 2.8 112 km S of False Pass, Alaska 03:03 UTC
9. 2.4 143 km SSE of False Pass, Alaska 20:02 UTC
10. 2.4 173 km SE of Akutan, Alaska 11:00 UTC
11. 2.4 157 km ESE of Akutan, Alaska 01:40 UTC
12. 2.7 147 km S of False Pass, Alaska 02:59 UTC
13. 2.8 146 km S of False Pass, Alaska 07:49 UTC
14. 2.4 112 km S of False Pass, Alaska 16:43 UTC
15. 2.5 162 km S of False Pass, Alaska 22:32 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 16:00 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 7,900 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.