193 km ESE of Atka, 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 950 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 350,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 16,000× the energy of this one
3. Magna, Utah 2020 M 5.7 11,000× the energy of this one
4. This earthquake M 3.0 about 950 lb of TNT

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 51.8414, -171.4463. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.8 171 km WSW of Nikolski, Alaska 06:43 UTC
2. 3.8 171 km WSW of Nikolski, Alaska 05:43 UTC
3. 3.1 172 km WSW of Nikolski, Alaska 19:07 UTC
4. 3.2 178 km E of Atka, Alaska 20:00 UTC
5. 2.7 168 km SW of Nikolski, Alaska 21:46 UTC
6. 3.2 172 km WSW of Nikolski, Alaska 19:31 UTC
7. 2.6 202 km ESE of Atka, Alaska 11:10 UTC
8. 2.9 178 km E of Atka, Alaska 09:03 UTC
9. 2.9 179 km ESE of Atka, Alaska 05:54 UTC
10. 3.6 210 km SW of Nikolski, Alaska 06:13 UTC
11. 2.9 212 km SW of Nikolski, Alaska 01:16 UTC
12. 2.8 189 km WSW of Nikolski, Alaska 10:07 UTC
13. 2.8 184 km E of Atka, Alaska 14:46 UTC
14. 2.9 182 km SW of Nikolski, Alaska 03:03 UTC
15. 3.4 177 km WSW of Nikolski, Alaska 07:11 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 18:52 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 6.0 on 2024-05-19 — it released about 32,000 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.