175 km SW of Nikolski, Alaska

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 22 km (14 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 1,300 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 250,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 11,000× the energy of this one
3. Magna, Utah 2020 M 5.7 7,900× the energy of this one
4. This earthquake M 3.1 about 1,300 lb of TNT
5. Around the size people start to feel M 3.0 this one released 1.4× 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 6.0 on 2024-05-19 — about 22,000 times the energy of this one.

Before 2016, the USGS record lists 70 earthquakes of M5 or more within 50 km; the five largest:

1. 6.2 179 km SW of Nikolski, Alaska · 29 km SSE of this epicentre Jun 4, 1956
2. 6.2 Fox Islands, Aleutian Islands, Alaska · 43 km SSE of this epicentre Mar 10, 1957
3. 6.1 185 km ESE of Atka, Alaska · 46 km WSW of this epicentre Dec 6, 1930
4. 6.1 207 km ESE of Atka, Alaska · 46 km SW of this epicentre Mar 13, 1957
5. 6.1 Fox Islands, Aleutian Islands, Alaska · 22 km SSE of this epicentre Jan 11, 1961

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 51.9986, -170.9351. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 3.4 130 km WSW of Nikolski, Alaska 11:04 UTC
2. 3.4 127 km SW of Nikolski, Alaska 10:05 UTC
3. 3.7 183 km SW of Nikolski, Alaska 02:29 UTC
4. 3.1 157 km SW of Nikolski, Alaska 20:32 UTC
5. 3.2 178 km SW of Nikolski, Alaska 11:53 UTC
6. 3.5 158 km SW of Nikolski, Alaska 16:52 UTC
7. 3.9 166 km WSW of Nikolski, Alaska 00:44 UTC
8. 3.6 167 km WSW of Nikolski, Alaska 10:00 UTC
9. 3.5 145 km SW of Nikolski, Alaska 02:38 UTC
10. 2.9 170 km WSW of Nikolski, Alaska 21:48 UTC
11. 3.3 172 km SW of Nikolski, Alaska 19:15 UTC
12. 3.7 159 km WSW of Nikolski, Alaska 05:02 UTC
13. 3.2 169 km WSW of Nikolski, Alaska 03:18 UTC
14. 4.0 166 km SW of Nikolski, Alaska 08:47 UTC
15. 2.8 171 km WSW of Nikolski, Alaska 06:43 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 13:03 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.