40 km SE of Kokhanok, Alaska

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

At this magnitude and depth it was probably too small to be felt, even directly above it. 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 1,100 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 6.7 310,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 14,000× the energy of this one
3. Magna, Utah 2020 M 5.7 9,900× the energy of this one
4. This earthquake M 3.0 about 1,100 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.

For this area

The largest earthquake within 50 km since 2016 was M 5.0 on 2023-07-28 — about 880 times the energy of this one.

Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:

1. 6.0 62 km SSE of Kokhanok, Alaska · 35 km SSW of this epicentre May 4, 1937
2. 5.6 72 km S of Kokhanok, Alaska · 49 km SSW of this epicentre Nov 14, 1974
3. 5.6 62 km SE of Kokhanok, Alaska · 24 km SSE of this epicentre Mar 23, 1984
4. 5.5 73 km SSE of Kokhanok, Alaska · 37 km S of this epicentre May 21, 1964
5. 5.2 70 km SE of Kokhanok, Alaska · 31 km SSE of this epicentre Jun 10, 1964

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 59.1908, -154.2536. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.0 22 km SSE of Kokhanok, Alaska 07:07 UTC
2. 2.5 71 km SE of Kokhanok, Alaska 00:32 UTC
3. 1.8 54 km SSE of Kokhanok, Alaska 12:20 UTC
4. 2.1 17 km SSE of Pope-Vannoy Landing, Alaska 05:06 UTC
5. 2.0 60 km SSE of Kokhanok, Alaska 15:12 UTC
6. 2.2 66 km SE of Kokhanok, Alaska 18:22 UTC
7. 2.3 62 km SE of Kokhanok, Alaska 14:27 UTC
8. 1.9 58 km SE of Kokhanok, Alaska 07:30 UTC
9. 2.3 54 km SE of Kokhanok, Alaska 03:31 UTC
10. 2.3 62 km SSE of Kokhanok, Alaska 13:04 UTC
11. 2.2 18 km SSE of Pope-Vannoy Landing, Alaska 05:18 UTC
12. 2.2 68 km SE of Kokhanok, Alaska 09:35 UTC
13. 2.5 51 km SSE of Kokhanok, Alaska 05:25 UTC
14. 1.9 19 km S of Pope-Vannoy Landing, Alaska 16:11 UTC
15. 1.9 67 km SE of Pope-Vannoy Landing, Alaska 06:33 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 20:23 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.