84 km SE of Halibut Cove, 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 13 km (8 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 240 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.6 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 63,000× the energy of this one
2. Magna, Utah 2020 M 5.7 45,000× the energy of this one
3. Around the size people start to feel M 3.0 4× the energy of this one
4. This earthquake M 2.6 about 240 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

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

1. 6.6 124 km SSE of Halibut Cove, Alaska · 45 km S of this epicentre Apr 23, 1968
2. 6.2 43 km ESE of Halibut Cove, Alaska · 44 km NNW of this epicentre Nov 3, 1945
3. 5.7 121 km S of Lowell Point, Alaska · 45 km E of this epicentre Mar 28, 1964
4. 5.7 125 km SE of Halibut Cove, Alaska · 44 km ESE of this epicentre Apr 2, 1964
5. 5.3 119 km S of Lowell Point, Alaska · 49 km E of this epicentre Sep 9, 1968

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 59.0493, -150.1840. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.2 105 km SSE of Halibut Cove, Alaska 22:40 UTC
2. 2.4 99 km SE of Halibut Cove, Alaska 07:05 UTC
3. 3.0 118 km SE of Halibut Cove, Alaska 16:18 UTC
4. 2.0 97 km SE of Port Graham, Alaska 14:32 UTC
5. 2.3 63 km SE of Halibut Cove, Alaska 19:48 UTC
6. 2.3 58 km SE of Halibut Cove, Alaska 19:18 UTC
7. 2.1 81 km SE of Halibut Cove, Alaska 22:27 UTC
8. 2.4 75 km SE of Halibut Cove, Alaska 08:47 UTC
9. 2.3 74 km SSE of Halibut Cove, Alaska 23:13 UTC
10. 3.2 60 km SSE of Halibut Cove, Alaska 01:51 UTC
11. 1.9 55 km SE of Halibut Cove, Alaska 17:04 UTC
12. 3.4 121 km SE of Port Graham, Alaska 22:57 UTC
13. 2.0 74 km ESE of Halibut Cove, Alaska 18:50 UTC
14. 2.2 106 km SE of Halibut Cove, Alaska 17:54 UTC
15. 2.0 73 km SE of Halibut Cove, Alaska 14:35 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 12:20 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.