79 km ESE of Sand Point, 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 8 km (5 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

The largest earthquake within 50 km since 2016 was M 7.6 on 2020-10-19 — about 32,000,000 times the energy of this one.

Before 2016, the USGS record lists 22 earthquakes of M5 or more within 50 km; the five largest:

1. 7.4 54 km SE of Sand Point, Alaska · 32 km W of this epicentre May 31, 1917
2. 6.6 72 km SE of Sand Point, Alaska · 18 km SW of this epicentre Oct 16, 1932
3. 6.6 104 km SSE of Perryville, Alaska · 47 km E of this epicentre Nov 11, 1938
4. 6.6 85 km SE of Sand Point, Alaska · 32 km SSW of this epicentre Oct 9, 1985
5. 6.5 94 km ESE of Sand Point, Alaska · 16 km SE of this epicentre Feb 14, 1983

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 55.0209, -159.3787. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.0 65 km S of Ivanof Bay, Alaska 08:05 UTC
2. 2.4 69 km ESE of Sand Point, Alaska 03:26 UTC
3. 2.2 94 km SE of Sand Point, Alaska 06:32 UTC
4. 2.7 76 km S of Perryville, Alaska 00:31 UTC
5. 1.8 76 km ESE of Sand Point, Alaska 23:51 UTC
6. 1.6 75 km ESE of Sand Point, Alaska 23:18 UTC
7. 2.3 72 km ESE of Sand Point, Alaska 13:11 UTC
8. 2.9 94 km S of Perryville, Alaska 04:33 UTC
9. 2.2 93 km SSE of Sand Point, Alaska 01:57 UTC
10. 1.9 76 km ESE of Sand Point, Alaska 15:35 UTC
11. 2.0 80 km ESE of Sand Point, Alaska 15:31 UTC
12. 1.8 109 km SE of Sand Point, Alaska 11:59 UTC
13. 2.6 103 km ESE of Sand Point, Alaska 23:45 UTC
14. 2.0 84 km SSE of Sand Point, Alaska 14:45 UTC
15. 1.6 94 km SE of Sand Point, Alaska 03:25 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 13:29 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.