172 km E of Atka, Alaska

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth, people at rest would likely notice it out to about 146 km (91 mi) from the epicentre. Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

How big was it?

This earthquake released about 170 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.7 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 1,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 45× the energy of this one
3. Magna, Utah 2020 M 5.7 32× the energy of this one
4. This earthquake M 4.7 about 170 tons of TNT
5. Around the size people start to feel M 3.0 this one released 350× 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.

For this area

The largest earthquake within 50 km since 2016 was M 4.9 on 2024-04-10 — about 2 times the energy of this one.

Before 2016, the USGS record lists 54 earthquakes of M5 or more within 50 km; the five largest:

1. 7.3 Fox Islands, Aleutian Islands, Alaska · 14 km SW of this epicentre Jun 24, 2011
2. 6.9 170 km E of Atka, Alaska · 5 km NNW of this epicentre Sep 2, 2011
3. 6.3 143 km E of Atka, Alaska · 34 km WSW of this epicentre Apr 5, 1957
4. 6.1 185 km ESE of Atka, Alaska · 31 km SSE of this epicentre Dec 6, 1930
5. 6.1 157 km ESE of Atka, Alaska · 35 km SW of this epicentre Jul 13, 1959

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 52.1275, -171.6751. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 3.2 166 km WSW of Nikolski, Alaska 23:07 UTC
2. 3.1 172 km WSW of Nikolski, Alaska 19:07 UTC
3. 3.2 178 km E of Atka, Alaska 20:00 UTC
4. 3.9 167 km WSW of Nikolski, Alaska 08:28 UTC
5. 2.6 202 km ESE of Atka, Alaska 11:10 UTC
6. 2.6 150 km E of Atka, Alaska 20:46 UTC
7. 2.9 178 km E of Atka, Alaska 09:03 UTC
8. 2.9 179 km ESE of Atka, Alaska 05:54 UTC
9. 2.8 189 km WSW of Nikolski, Alaska 10:07 UTC
10. 2.8 184 km E of Atka, Alaska 14:46 UTC
11. 3.4 177 km WSW of Nikolski, Alaska 07:11 UTC
12. 2.8 188 km E of Atka, Alaska 19:49 UTC
13. 3.8 138 km E of Atka, Alaska 14:35 UTC
14. 2.9 175 km E of Atka, Alaska 04:31 UTC
15. 3.1 173 km E of Atka, Alaska 04:13 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 05:54 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

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.