192 km SE of Nikolski, 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 51.9627, -166.5289. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 3.3 157 km ESE of Nikolski, Alaska 13:38 UTC
2. 2.6 150 km ESE of Nikolski, Alaska 10:31 UTC
3. 2.9 152 km ESE of Nikolski, Alaska 08:41 UTC
4. 2.9 152 km ESE of Nikolski, Alaska 08:35 UTC
5. 3.3 208 km ESE of Nikolski, Alaska 02:23 UTC
6. 2.1 162 km ESE of Nikolski, Alaska 03:01 UTC
7. 3.2 196 km ESE of Nikolski, Alaska 01:27 UTC
8. 3.4 207 km SE of Nikolski, Alaska 21:49 UTC
9. 3.0 180 km SE of Nikolski, Alaska 00:00 UTC
10. 2.2 212 km SE of Nikolski, Alaska 15:10 UTC
11. 2.2 Fox Islands, Aleutian Islands, Alaska 05:20 UTC
12. 2.8 149 km ESE of Nikolski, Alaska 02:24 UTC
13. 2.7 189 km SE of Nikolski, Alaska 15:21 UTC
14. 2.9 184 km SE of Nikolski, Alaska 08:53 UTC
15. 2.4 219 km SE of Nikolski, Alaska 16:49 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 17:50 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 2017-05-24 — 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.